Poole Harbour is a large body of water dotted with five small wooded islands: Brownsea, the biggest, along with Furzey, Green, Round, and Long. Its southern and western edges are lined with creeks and mudflats, whereas the northern and eastern sides feature development. The extensive estuary, spanning 38 square kilometres (15 sq miles), appears like an inland lake during high tide, with branches spreading out into the surrounding heaths. Despite its size, it is quite shallow, with an average depth of just under half a metre, and can only be crossed through its clearly marked channels. It attracts numerous leisure boats, supported by more than a dozen yacht clubs and marinas. The harbour bustles with various vessels, and its safe sailing conditions draw people of all ages and skill levels eager to enjoy the water.

However, it has its quirks, and the key considerations when planning an approach to Poole Harbour are as follows:

• 1. Strong Ebb Tides: During spring ebb tides, tidal currents through the narrow entrance can reach 4-5 knots, so timing the entry for a favourable moment is crucial. Boats coming from the south may also encounter a strong tidal race near Old Harry Rocks and Handfast Point.


• 2. Wind Against Tide: The most dangerous conditions occur when strong easterly or south-easterly winds oppose a spring ebb tide. This produces steep, breaking waves, heavy swell, and rough chop at the harbour entrance, especially near Poole Bar and the Swash Channel. Alternatives such as the East Looe Channel can also be particularly risky in high winds or at low water.


• 3. Use the Boat Channels: Leisure craft should use a Boat Channel that runs parallel to the commercial shipping channel at the outer entrance. Once inside Poole Harbour, smaller yachts should join the Boat Channel starting northeast of Brownsea Island and following the southwest side of the commercial fairway to Poole's approach channel.


• 4. Commercial Shipping Encounters: The Bramble Bush Bay Chain Ferry has the right of way and operates continuously across the entrance. Pass well behind the ferry and never attempt to cross in front of it to avoid being swept into its chains. Large commercial vessels also use the Swash Channel, have limited manoeuvrability, and have absolute right of way.


• 5. Avoid Low Water and Grounding: Because it is so shallow, it is important to keep to the marked channels, particularly at low tide around Hook Sands, the Training Bank, or moving sandbanks.

In case of any emergency in the harbour, please contact the Harbour Control Officer using: [VHF]: Ch. 14 (or 16) [Poole Harbour Control], +44 (0)1202 440 230, harbourcontrol@phc.co.uk.


APPROACHING POOLE BAY

Coastal directions are provided in the Start Point to Selsey westbound or eastbound coastal descriptions.




Coastal guidance for this sailing area is available in The Needles to Portland Bill . Poole Bay is easily recognisable by the high cliffs of Anvil Point in its south-west corner and the sweeping northern coastline, mostly lined with Bournemouth buildings. As you get closer, the rocks of Old Harry at Handfast Point, located south-west of the bay's centre, serve as a clear landmark. Just over a ½ mile north of Old Harry, the Swash Channel begins, guiding ships into the north-east part of Poole Bay, where Poole Harbour's entrance is situated.




Treat Old Harry Ledges with respect, and avoid approaching its cliffs closer than ¼ of a mile. A race extends east from Handfast Point during the ebb, or west-going stream, which runs south of Handfast Point in Poole Bay. Eddies may form near the point, especially in an easterly or south-easterly direction.



THE SWASH CHANNEL


The Swash Channel is the main dredged deep‑water approach into Poole Harbour, running along the inside of Poole Bay and guiding vessels safely from the open sea toward the harbour entrance at Sandbanks / North Haven Point. Our navigational guidance begins at Poole Bar No. 2 Port buoy Fl R.2s, which marks the entrance to the Swash Channel.




From here, the channel is easily identifiable by a series of closely spaced, lit buoys that guide vessels northwest for 2 miles toward the banks at Poole Harbour's entrance. Additionally, just under ¾ of a mile above, a protective training wall borders the channel on its south-western side and is marked by beacons.



The Training Bank is submerged at half-tide but is clearly marked by beacons, with the first beacon lit and showing 2 FR (vert). Between these beacons and the main shipping's Swash Channel lies a separate Boat Channel. The Swash Channel is about 130 metres wide, with a consistent depth of 7.5 metres.





Vessels coming from the east can bypass the first waypoint and enter the Swash Channel slightly further north. The main hazard is Hook Sands, also known as Hook Sand, a large, dynamic sandbank on the eastern side of the Swash Channel, directly opposite the Sandbanks peninsula. Strong easterly gales shift its sands, and charted depths can vary. This shifting form, combined with the shallow bars, generates strong tidal currents that can kick up choppy, potentially dangerous waters. Navigating around it requires attention to buoyage and tidal conditions.




However, you can cut in from the east, ⅓ of a mile above, by passing close south of the unlit South Hook South Cardinal buoy. Expect at least 2.5 metres of water south of the mark. With a rise and good conditions, you can cut in much further north, keeping a keen eye on the sounder. Alternatively, in favourable conditions, you may use the East Looe Channel and run in along the Sandbanks peninsula.




The Boat Channel runs between the training wall and the port marks on the south-west side of the Swash Channel. It is reserved for pleasure craft and fishing vessels, helping to keep the Swash Channel clear for commercial traffic. The Boat Channel extends to Shell Bay and has at least 3 metres of water. Leisure craft are requested to use the Boat Channel whenever possible, particularly when the main fairway is occupied by larger vessels.



THE EAST LOOE CHANNEL


The East Looe Channel, often called the East Looe Cut, is a shallower secondary approach to the Poole Harbour entrance, used by coastal leisure vessels arriving from the east. It runs close to the Sandbanks shoreline and across the northern edge of Hook Sands. The East Looe Channel has a minimum charted depth of 1.3 metres. Because easterly gales may shift the sands here, treat this charted depth with a seamanlike degree of caution. Newcomers are advised to allow a generous margin for clearance, but ample water should be available at mid to high tide.




In moderate to heavy easterly or south-easterly conditions, breaking waves can form over the shallow sands, making the channel uncomfortable or dangerous. That said, in favourable weather, at mid to high tide, the East Looe Channel is well marked and conveniently situated very close to the harbour entrance. It therefore offers an excellent cut from the east, removing the need for a long southern dogleg to the Bar Buoys, and can prove very useful when a strong ebb tide is running down the Swash Channel.




The East Looe Channel is marked by buoys, and a helpful local transit for identifying the eastern entrance marks is to keep the Sandbanks Hotel in line at roughly 260°. This alignment keeps the vessel near the first pair of buoys: East Looe EL No. 1 port buoy (Fl R.4s) and EL 2 (Fl G.5s). Visually identify these buoys, as the app's oceanic object positions and the charted positions may not be exact due to shifting sands and buoy relocations.




EL 1 and EL 2 lead over the bar to a second pair of buoys, EL 3 and EL 4. After passing through the latter pair, the water should start to deepen once again. Vessels should then turn to port and run parallel to the beach, about 100 metres off, to pass inside or to the north of the North Hook port buoy, Fl(2)R.5s. Continue along the shore to pass close south of the two substantial Green Beacons, 2F.G vert, on the heads of the groynes fronting the shore. Then enter the Swash Channel well north of the Swash (No. 9) west cardinal buoy, Q(9)15s, where the narrow 300m harbour entrance opens.







THE ENTRANCE TO POOLE HARBOUR


The harbour's 300-metre-wide entrance lies ⅔ above between the low, sandy South Haven Point on the south side and the built-up Sandbanks peninsula, dominated by the enormous Sandbanks Hotel, on the north side.



From South Haven Point, adjacent to the final Training Wall Beacon and near the No. 8 and No. 7 Swash Channel buoys, through the entrance to the Bell Buoy, inside the harbour and opposite Brownsea Castle, is designated a 'Precautionary Area'. This status reflects the elevated risk posed by frequent large shipping on this blind bend, the chain ferry's operations, the convergence of several minor channels, swift tidal flows that reach a Spring rate of 4.5 kn, associated eddies, and the lack of space for a designated Small Boat Channel.




Added to these complications is a host of leisure boat activity with a 10-knot harbour speed limit, and, needless to say, the helm needs to be alert; you must exercise due caution. Leisure vessels should only cross the channel if safe to do so without impeding other traffic.




The Bramble Bush Bay Chain Ferry runs across the harbour entrance between South Haven Point and Sandbanks. The chain ferry has absolute right of way over all leisure vessels. A black ball hoisted at the forward end indicates its intention to move off the slipway, and a white strobe light flashes in the direction of travel when the engines are engaged. It is likewise easy to predict when the chain ferry is ready to depart, especially on the south side, by simply watching the Ro-Ro vehicles loading.




Likewise, all large commercial vessels, ships over 50 meters in length, must follow the charted leading line of 299°/119° through the harbour entrance. The deep‑draft alignment is designed to maintain steerage during peak tidal flows and to avoid the shallows known as Chapmans Peak, a spur with 4.3 meters over it that extends from the Sandbanks side of the channel. Small craft should stay clear of the entrance when a large vessel enters the Precautionary Area to keep the channel clear. If they cannot or are caught off guard, they should take appropriate action by preferably using the eastern side (Sandbanks/Green/East) when within the Precautionary Area, whether inbound or outbound, and proceed over Chapman's Peak with utmost caution.




Where outbound small craft have put themselves at risk of impeding shipping, and there is insufficient time to safely cross the channel, they may navigate "buoy to buoy" on the Studland/Red/West outer extremity of the channel or, if safe to do so, leave the channel entirely.


Once past the chain ferry and within the harbour, steer for the Brownsea East Cardinal buoy, Q(3)10s, off the southeast end of Brownsea Island. This buoy, together with another North Cardinal buoy located 200 metres southward, marks the east-facing junction of South Deep Channel and the Middle Ship Channel.


SOUTH DEEP


South Deep runs along the southern shore of Brownsea Island and separates it from the long spit of Goathorn Point. West of Brownsea Island's southern shore and East of Goathorn Point and the Arne Peninsula, it is a narrow, shallow, well‑protected channel that serves as a secondary, non-commercial route compared to the main shipping fairway. It connects to the Wych Channel, east of Brownsea Island, and to the Blood Alley Lake area south of the island.




South Deep is entered 200 metres south of the Brownsea East Cardinal buoy, north of the No.14 buoy, Fl.R.5s, and its adjacent lit North Cardinal buoy, Q, marking the north end of the drying Stone Island. This shallow, narrow channel passes close north of the North Cardinal buoy, then the No. 1 Starboard Beacon, Fl.G.5s. The sandbanks and mudflats in this junction area are subject to drift.




Cross-check your depth sounder continuously rather than relying solely on any chartography. Likewise, you need careful tidal awareness and strict adherence to the buoys and beacons along the route; all principal marks are available in the app.


This commencement point by the No.1 Starboard Beacon provides access to the shallow-water anchorage of Blood Alley Lake, ¼ mile west, with its connected anchorage at Whiteground Lake, south of Brownsea Island . The approaches to the Blood Alley anchorages are no less than 1.7 metres CD, but quickly descend to 0.3 CD or less around the mouth of the channel.

An unlit north beacon, which marks the mouth of Blood Alley Lake, will then be seen a little less than 400 metres to the southwest. From this point, Blood Alley runs westward, marked by stakes on either side of the channel.

At high water, you can pass from Blood Alley Lake to Whiteground Lake, then continue south around Brownsea to the Wych Channel. A large drying area, down to 0.5 metres CD at the northwest end of Whiteground Lake and about 400 metres south of Pottery Pier, limits this route to shoal-draft vessels.

The first marks of South Deep, marked by port and starboard light-beacons, will be seen 400 metres southward of the No.1 Green Pile beacon. This area, between No.1 and South Deep, has the shallowest water with a least depth of 1.2 CD. Thereafter, the channel becomes deeper, generally holding 2.0m to 3.5m LAT, but it is narrow and flanked by steep-to-drying mudflats. It is marked by a combination of lighted/unlit lateral buoys and wooden perches/posts. South Deep falls within a designated Poole Harbour Quiet Area. A strict 6-knot speed limit applies year-round, and vessels must minimise wake/wash to protect wildlife and anchored craft.

Stay strictly within the posted channel; cutting corners will lead to quick grounding on soft mud and little harm, as it meanders along the mainland, passing between Goathorn Point and Furzey Island, then Cleavel Point and Green Island, and onward northward to fork into the Wych Channel via Ramshorn Lake. In addition to the marks along its path, a set of leading lights on a 305° alignment on the southeast side of Furzey Island leads into the island's commercial slip.

The Goathorn Point anchorage lies in South Deep between the harbour's south-eastern shore and Furzy Island. Several other anchoring opportunities exist as it bends around Poole Harbour's southern shore. Protected from swell and most wind directions, and with minimal wash from commercial shipping, it is considered the harbour's most scenic and best-loved small-craft channel, offering a quiet recess used for anchoring, mooring, and gentle transits rather than fast navigation.


MIDDLE SHIP CHANNEL


The Middle Ship Channel opens to the north of the Brownsea East Cardinal. It is Poole Harbour's main commercial fairway, running from the entrance past Brownsea Island to the Port of Poole and Town Quay. It is 105 metres wide and maintained at a depth of 7.5 metres. As the main channel for commercial vessels, it sees considerable commercial traffic, including Cross-Channel high-speed ferries and cargo vessels proceeding to and from the busy commercial port, harbour tour boats from Town Quay, and some MOD activity. As large vessels have restricted manoeuvrability and often require the full width of the channel, leisure craft should keep well clear in their presence and avoid crossing ahead of any ship. Likewise, stay out of the Turning Basin unless authorised.




From the Middle Ship Channel's commencement east of Brownsea Island, the fairway runs generally north for just under a mile. It then turns west-northwest around the Aunt Betty east cardinal and continues for 1¼ miles to Little Channel, which leads into Poole Town Quays. The Middle Ship Channel continues north to Brownsey Roads, ¼ mile farther on. The North Channel, the harbour's second principal channel, passes around the harbour’s east side and rejoins the Middle Ship Channel ½ mile before Poole Town Quay. The third principal channel is Wych Channel, which branches off ⅓ mile beyond the North Channel’s branch point. It passes north of Brownsey Island before rounding its west end.


NORTH CHANNEL


Proceeding northward along the Middle Ship Channel to Brownsey Roads, a ¼ of a mile above, and the second of the harbour's principal channels, the North Channel, is entered off the Middle Ship Channel. It branches off opposite Brownsea Castle, with the Bell Buoy (No.15) south cardinal, Q(6)+LFl.15s, marking the dividing point. After about 2 miles, the channel converges again with the Middle Ship Channel to the west of Parkstone Shoal, close west of the Diver (No. 25) west cardinal, Q(9)15s.




The North Channel runs east and then north of the Middle Ground and Parkstone shoals, and of the mudflats opposite that extend from the east and north sides of the harbour. It was once the harbour's main channel and was dredged to 4.0 metres in 1997. It is no longer maintained and is subject to silting, but it is well marked with lighted buoys and is at least 2 metres deep throughout.




The North Channel leads to the premier 5-Gold-Anchor Salterns Marina located in Lilliput on the north-eastern shore of Poole Harbour. It lies immediately off the North Channel, midway between the harbour entrance and Poole Town Quay.




A ⅓ of a mile further along the North Channel is the extensive Parkstone Yacht Club , located between Salterns Marina and Poole Town Quay. It is entered via a dredged ¼-mile-long approach channel that leads from the North Channel to its entrance, which is behind a wave screen. It receives visitors in club members' vacant berths.



WYCH CHANNEL



The Wych Channel branched off the Middle Ship Channel between the large No. 18 Port buoy, Fl.R.4s, and the No.20 Q.R., situated off the northeast corner of Brownsea Island. It then passes north of Brownsea Island and then west of it. Lines of yacht moorings indicate its deeper water, and stakes with red and green topmarks mark its edges. Although well marked, its deeper waters are easy to spot by the density of leisure-craft moorings along its length.




The Wych Channel carries at least 2.2 metres LAT for 2¼ miles as it passes north of the island, then around its west end to Pottery Pier at the west extremity. The moorings begin to thin as you pass an old ferry, permanently anchored and repurposed as a fish-processing raft, off the island's north-most point. Less than a ¼ mile west of the raft, the Wych turns south, where an east-facing beacon marks Will's Cut on its northern flank.




Will's Cut is a shallow north-south channel that connects the Wych and Middle Ship channels. A corresponding east cardinal beacon on the southern side of Middle Ship Channel, opposite the Little Channel leading to Poole Town Quay, marks its junction.




Will's Cut is clearly signposted, well marked by closely spaced stakes, and has a minimum draft of 0.5 metres CD. It offers shoal-draft vessels a convenient cut across the harbour.




Continue along the Wych southward, following the markings along the island's west side. Pottery Pier, situated on the western extremity of Brownsea Island, will be visible for the last ½ mile. It is possible to anchor off Brownsea Island in this area.





MIDDLE SHIP CHANNEL
Continued
Above the entrance to the Wych Channel, a Boat Channel has been established adjacent to the Middle Ship Channel to keep the main fairway clear. It lies on its south-west side, running between its port buoy and a series of unlit port hand beacons. The Boat Channel begins inside the large No. 18 Port buoy, off the northeast corner of Brownsea Island. It then runs northward, parallel to the Middle Ship Channel, before turning north-westward between a black/yellow/black east topmark beacon on the inside and the main fairways' Aunt Betty east cardinal buoy, Q(3)10s, on the outside. Apart from these two marks, the small boat channel beacons are unlit.




Recreational craft and fishing vessels must use the Small Boat Channel whenever possible to keep well clear of shipping in the main channel. Expect about 2.0 metres in the Small Boat Channel, but it can be as little as 1.5 metres near the beacons on its south-western side.





The small boat channel terminates opposite the entrance to the Little Channel, which branches north from the inner end of Middle Ship Channel at Stakes No. 29 South Cardinal buoy. From here, the Little Channel leads the final ¼ of a mile to the Town Quay .




It passes the entrance to the Port of Poole Marina , the quays of the Port of Poole on the west side, and the head of the enclosing breakwater at the entrance to Poole Quay Boat Haven on the east.



The harbour speed limit drops from 10 knots to 6 knots in the Little Channel and beyond, extending up to Holes Bay. There, about one mile above Town Quay, you'll find the large-scale MDL Cobb's Quay marina.





WAREHAM CHANNEL
Proceed past the Port of Poole and watch for any signs of vessel movement. If a vessel starts to move, clear the Turning Basin immediately. Commercial vessels are restricted by depth and channel width, leaving them with very limited ability to deviate from their manoeuvre. As a useful rule of thumb, if a ferry is approaching, departing, or preparing to turn, stay clear of the Turning Basin until the manoeuvre is complete.



Hamworthy's Poole Yacht Club is located at the west end of the Port of Pool Ferry Terminal. The club welcomes visitors from recognised clubs and, when space allows, offers berths to visitors when the usual berth holders are absent.




Proceed between the Hutchins WH1 Fl.G.3s green starboard and WH2 Fl.R.2s port buoys. The fairway is marked by WH3 Fl.G.5s green starboard and WH4 Fl.R.4s port buoys, located near the north shore in this tideway. 1 mile north-westward along the shoreline from Port of Poole, opposite Gold Point, and about 300 meters northwest of the buoys, is Moriconium Quay on the north shore.




Its high-rise buildings make it conspicuous. Lake Yard Marina , which accommodates visitors on its numerous moorings, is the second marina, situated directly behind and connected to the privately owned Moriconium Quay.




Opposite the Lake Yard Marina lies the attractive Arne Peninsula. About 1½ miles wide, it features woods, fields, and heathland, most of which is designated as a nature reserve. The peninsula extends nearly 3 miles into the harbour from the southern shore, narrowing the tidal passage between Gold Point at the north and the Hamworthy shoreline to less than ½ a mile.




You will see several large-ship mooring buoys ¼ of a mile ahead. Keep these to port, with the green starboard buoy WH5 Fl.G.3s to the north. Pass this buoy on its proper side. The channel then turns south-west, running near the northwest shore of Arne Peninsula as it passes Russell Quay.





Beginning at Russell Quay, the channel runs almost straight for 1½ miles along the expansive Wareham Reach, providing views of the heathland on the Arne Peninsula and the Purbeck Hills. Several lit buoys on the starboard and port sides guide the way. A pair of lit red Fl.R.4s and green Fl. R. 4s posts, with topmarks, delineate the boundary of Poole Harbour north of the marshy Gigger's Island.




Following these posts, the channel veers south before turning northwest again, passing Bower Point and Turner's Cove. It then curves south-west, south of Swineham Point, where the river broadens between reed boundaries. Stay along the middle south of Swineham Point. All craft proceeding into the River Frome will, by necessity, work the tides.




Poole Harbour features a double high water with a prolonged tidal stand/plateau lasting roughly 3–4 hours. This provides a significantly wider window of deeper water for the run up the river than on typical tidal rivers in the English Channel. It is also important to slow down in the River Frome, as although Poole Harbour generally observes a 10-knot limit, the River Frome has a strict 4-knot speed limit. Local authorities and Poole Harbour Commissioners (PHC) enforce this closely to prevent wash damage to fragile reed beds and riverbanks. As you exit the main Wareham Channel into the Frome, navigation markers transition from standard IALA buoyage to smaller, spindly post/perch markers through the marshland.




The River Frome is marked by withies and mooring buoys; stay in the channel, which often runs closer to established moorings than to the inner reedy shores. On river bends, stay clear of bank slippages. The outer bends offer the best depths as the River Frome meanders for about 1¾ miles towards Wareham, but beware of Redcliff bend, as noted below, which is the exception to the rule. Since the river is quite narrow and the 4-knot speed limit appears optimistic, the journey to Wareham will take nearly an hour, but it promises to be pleasant.




Ridge Wharf Yacht Centre , which accommodates visiting boats, will be passed on the southern shore ¾ of a mile upriver from Swineham Point. A ½ mile upstream at the Redcliff bend, just before the Frome turns 90° to pass the pontoons of Redcliff Yacht Club, is the river's primary danger. This is a 'hard contact' underwater steel pipe that crosses the river on the final approach to the Redcliff bend.




The pipe lies adjacent to the slipway at Redcliffe Farm on the eastern shore, crossing the river to a point where a warning sign on the opposite western bank marks its position, directly opposite the slipway. The sign alerts mariners to the submarine pipeline crossing and warns against anchoring, trawling, or running aground on the structure.




However, the pipe poses its main danger on the river's eastern side. Extending from that side, it dries to 0.3 metres just beyond the slipway. It poses a serious grounding risk for boats sweeping wide into the bend or travelling close to the eastern bank at low or mid-tide. An hour before high water, the mean depth over the pipe's shallowest point is 1.22 metres, so avoid the eastern shore near the slipway, particularly within two to three hours either side of low water.




Anyone operating near the margins should take extreme care when approaching the Redcliff bend. Many unsuspecting visitors have hit the pipe after following the usual advice or instinct to stay outside bends for deeper water. Here, it is best to break that age-old rule: pass well over to the river's west side, or take the inside approach to the right-hand bend.




Redclyffe Yacht Club will then be passed beyond the bend, and they accommodate visitors where they can find a vacant space. From the club, Wareham is only a ½ mile upstream and will be clearly visible above the swaying reeds that flank the river.




A drying berth is usually available alongside the historic town quay in Wareham . Avoid the well-marked Ferry Quay, as tourist launches use it constantly.




The town's historic South Bridge marks the effective head of navigation for vessels of any air draft. Boats able to pass beneath it will reach the river's tidal limit about ½ mile beyond the Town Quay. Physical clearance gauge boards at the bridge approaches show the exact real-time headroom above the current water level. Expect the following maximum clearance when proceeding upriver.

South Bridge (Wareham Bridge)

• • Mean High Water Springs (MHWS): Approximately 2.0 m to 2.1 m


• • Mean Low Water (MLW): Approximately 3.5 m to 3.8 m

This clearance applies only directly under the centre of the main arch and it drops off rapidly towards the sides.


LISTED WAYPOINTS
The complete course is 9.18 miles from the waypoint 'No. 2 Bar Bouy' to 'Swineham Point' tending in a west north westerly direction (reciprocal east south easterly).























POOLE HARBOUR TIDES
Poole has unusual tides with a very small tidal range: neaps 0.4m; springs 1.5m, with what resembles a HW stand at Neaps and a double HW at Springs. When LW occurs between 0230 and 0830 or 1430 and 2030, HW Springs is about 5hrs after LW, followed by a second lower HW 4hrs later, returning to about LW 3 hours later. When LW occurs between 2030 and 0230 or 0830 and 1430, HW Neaps is just 3 hours 30 minutes before the next LW. The tide then rises abruptly for 4 hours, then gradually for almost three hours, giving a stand before peaking abruptly 2 hours later. This is very gradual and scarcely perceptible on neaps, as the entire mean range is only 0.4 m.

MHWS 2.1m MHWN 1.6m MLWN 1.6m MLWS 0.3m
Town Quay Mean Level 1.6 metres
Sea levels within the harbour can rise by as much as 0.2 metres when strong east-to-southwest conditions establish themselves for an extended period. Conversely, established westerly to northeast winds can lower sea levels by 0.1m. Poole Harbour is highly subject to barometric pressure, which can alter tide heights by as much as 0.3 metres.

What is the best sailing time?

May to September is the traditional UK sailing season, with June and July offering the best weather. The amount of bad weather varies widely from year to year. The British Isles' weather is highly variable because they sit between the Atlantic Ocean and a large continental European landmass. As a result, the entire area lies within a zone where five main air masses meet and alternate:

• • Tropical Maritime Air Mass - from the Atlantic


• • Polar Maritime Air Mass - from Greenland


• • Arctic Maritime Air Mass


• • Polar Continental Air Mass - from central Europe


• • Tropical Continental Air Mass - from North Africa

Air masses can come from any direction, bringing a wide range of weather and creating fronts where they meet. Fine summer weather is typically punctuated by the passage of Atlantic depressions, bringing periods of strong wind and rain and sometimes poor visibility.

Gales, however, rarely come as a surprise, as forecasters usually warn of them well in advance. Good weather windows of 48 hours are easy to predict, but beyond that, the chance of change increases. Winters see a predominance of wind and rain. Still, many weekenders enjoy the protected waters of Poole Harbour, with reduced boating activity and berthing fees in the off-season.

Across the British Isles, the prevailing winds are from the southwest. Fogs are common across the English Channel, forming on both the English and French coasts. In summer, they usually obscure the land only in the morning and are readily dispersed by heat or a light breeze. However, the moist haze, driven in by westerly winds from the sea, tends to linger and requires stronger winds for dissipation. In the eastern part of the Channel, the land is rarely entirely free of mist. The only exception occurs when the wind is from the northeast, creating a mist-free coastline that is highly distinctive from a great distance.

Are there any security concerns?

Based on the author's personal experience, vessels left unattended on isolated harbour moorings can be subject to break-ins. Aside from that, it is a peaceful place to visit.

With thanks to:

eOceanic