OVERVIEW
Although this is the principal route to enter Saint Mary's Pool replete with ample marks it is not without hazard for the unwary. The hidden danger for a vessel cutting in from the east, well clear of this route, is the unmarked Gilstone rock located on the southern end of foul ground extending from Tolman Point 0.4 of a mile eastward from Peninnis Light. It uncovers and dries to 4 metres.



The flanking island landmasses that serve to provide ready assurance of correct navigation can also serve to make it one of the more challenging approaches when it comes to adverse tides. The narrow channel making Saint Mary's Sound a rough and unpleasant body of water at times on account of the funnelling effect between the large islands. Tidal streams can attain rates of up to 2kn and winds and swell from southwest round through west to northwest and a strong east to southeast wind-against-tide can make it very unpleasant. Likewise, heavy southwest round through west to northwest winds can create a rough sea over the shoals at the northwest end of the passage.




Nevertheless, it is more than manageable in all reasonable conditions. Should the seas in the sound happen to look uncomfortable during an approach there is always the option to duck into the adjacent The Cove . This provides an ideal anchorage to get squared away and await a turn of the tide or change of conditions. As such this route can be relied upon by all newcomers and all vessels approaching from east or south.

Finally, although we have linked this directly to the Coastal Overview for Land's End to Isles of Scilly we do not want to suggest this is the defacto approach that should be taken to Saint Mary's Road. Alternative approaches can be made, given suitable weather and state of tide, via Crow Sound to St Mary's Pool from the east and the Scillonian III passenger ferry takes this path at high water. Likewise, Broad Sound or the North West Passage provide well-marked approaches from other directions.




As discussed in the Coastal Overview for Land's End to Isles of Scilly , the Admiralty transits that marking St Mary's Sound and Road can be exceedingly difficult to make out for newcomers and the buoyed channel is well marked so they are no longer needed.




Nevertheless, the St Mary's Sound transit, if spotted, keeps a vessel well clear of any dangers. It also offers a good confirmatory eyeball check for navigation and serves as a useful gauge for the helm to counter a tidal cross-set when making way up the sound. So hence we have plotted the course of this route along the Admiralty 307° T St Mary's Sound alignment of the charted western extremity of Great Minalto with North Carn of Mincarlo for the first leg.




We chose not to use the charted Admiralty transit, of St Martin's daymark in line with the northern summit of Creeb Rock on 040.5° T as it added unnecessary distance to a leisure craft route.


SAINT MARY'S SOUND


From the Saint Mary's Sound Waypoint, Peninnis Light, Fl.20s36m17M a white round metal tower on a black metal framework tower, will be clearly visible and the lit 'Spanish Ledge' East Cardinal Mark, Q(3)10s, about a mile away should be visible.

The waypoint is on the 307° T alignment of the western extremity of Great Minalto with North Cam of Mincarlo that leads through the Sound. These are the first substantive rocks that will be seen up St Mary's Sound, to the westward of the Isle of Samson, Great Minalto, 7 metres front, and Mincarlo, 16 metres rear, should be in line. The handful of rocks close west and around them is a scattering of small heads at best at low water.



If the transit is difficult to discern steer for the 'Spanish Ledge' East Cardinal Mark that is passed to port
as it is moored very close south-westward of the leading line through the sound.




Peninnis Light Fl.20s36m17M, a white round metal tower on a black metal framework tower, will be clearly visible on Peninnis Head. The head is steep too but it has Pollard Rock, that dries 1.8 metres at low-water springs, lying about 60 metres south of its inner head so stand a couple of hundred metres out from it.




This approach is well clear of the Gilstone, that is about 400 metres eastward of the 8 metres high Carrickstarne, that uncovers and dries to 4 metres.





A mile in is the 'Spanish Ledge' East Cardinal Mark, Q(3)10s that is passed to port. It is moored north-eastward of Spanish Ledges which are 400 metres in extent and awash at low-water springs. On the approaches to shallower waters keep a sharp eye for lobster pots.




Leaving Spanish Ledge to port steer to pass the starboard beacon 'Woolpack' FL.G.5s well to starboard - note on older charts the may be listed as a cardinal mark. The beacon stands on one of two heads of Woolpack Rock that projects nearly 300 metres southwestward from Woolpack Point on St Mary’s Woolpack Point. The rock dries to 0.6 meters a little before low water. Northwestward of Woolpack point, the coast of St. Mary's island is foul to a distance of 150 metres.




Then leave the lit Bartholomew red beacon, Q.R, and red can buoy on 'N. Bartholomew' Fl. R.5s, lying about a ½ mile north-westward of Spanish ledges, to port. The Bartholomew ledges consist of two shoals 400 metres in extent and include several rocky heads which near the beacon dry at low-water springs to 0.6 metres.





The 'N Bartholomew' port buoy Fl. R.5s, marks an isolated northern section called North Bartholomew. It is separated from the southern shoal by a deep channel and with 3.4 metres over it that is more of a concern for commercial shipping. However, during a westerly swell, the sea rolls heavily in the vicinity of these shoals, and boats should keep well clear of them.






SAINT MARY'S ROAD



Passing between 'N Bartholomew' and the 3-metre Steval Rock, which represents the western extremity of St Mary's Island, leads into Saint Mary's Road. It lies westward of the island of St Mary's and at this point it is possible to simply turn northward and continue standing out 300 metres from the shoreline to clear its dangers. With the exception of the deep Woodcock Ledge, with 2.7 metres over it LAT, there are no hazards from the Bartholomew Ledge buoy.



The Woodcock Ledge is more of a concern for deep commercial vessels so it is not necessary to continue offshore to the charted Admiralty Transit, of St Martin's daymark in line with the northern summit of Creeb Rock on 040.5° T that leads north-westward of this rock. Our waypoints cut inside it, passing between it and the shore and if there is any concern, or deep-draught yachts arriving at the bottom of the tide with a surge, feel free to continue to the Admiralty turn point where St Martin's Daymark on the summit of Creeb 040° T intersects the Admiralty 307° T alignment of the charted western extremity of Great Minalto with North Carn of Mincarlo. The following St. Mary's Road transit intersection waypoint is on this transit.

St. Mary's Road transit intersection waypoint Position: 49° 55.196' N, 006° 19.460' W




Either way the harbour is about ¾ a mile away at this point and its two lateral marks of the entrance channel will soon become visible. The harbour's port 'Bacon Ledge' buoy, Fl(4)R.5s, is moored 100 metres southwest of the shoal called the Bacon Ledge that is the final hazard on the approach on the approach to Saint Mary's Pool .




The path through the lateral marks is also supported by a charted entry transit that leads south of Beacon Ledge. This is set on Mount Flagon on the line of bearing 097.3° T of white beacons, with a triangle top mark pointing upward, and an 'X' topmark on the skyline. The final waypoint is set upon this transit.

LISTED WAYPOINTS
The complete course is 2.79 miles from the waypoint 'Saint Mary's Sound' to 'St Mary's Harbour' tending in a north north westerly direction (reciprocal south south easterly).

What is the best sailing time?

May to September is the traditional UK Sailing season with June-July offering the best weather. The British Isles weather is highly variable, and the amount of bad weather varies quite widely from year to year. This is because they are islands positioned between the Atlantic Ocean and the large landmass of continental Europe. As a result, the entire area lays under an area 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

Depending on the movements of the jet stream, any and all of these air masses can come in over the isles, creating weather fronts where they meet and bringing with them all types of weather.

The prevailing winds for the British Isles as a whole are from the western quarter which generally blows for two-thirds of the year predominantly from the southwest. Gales from the westward are felt in all seasons, but from November to March, inclusive, they are most frequent and generally last three or four days. Of these, a southwest gale is considered to be the most powerful system. The winter period is largely characterised by wind and rain.

The fine summer weather of the sailing season is typically punctuated by the passage of an Atlantic depression that bringing periods of strong wind and rain, and sometimes poor visibility. These gales rarely cause surprises as they are usually forecasted well in advance. Good weather windows of 48 hours are easy to predict but any longer than that there's an increasing chance of change.

Fogs are frequent in all parts of the Channel and are formed both on the English and French coasts. In summer they only obscure the land in the morning and are readily dispersed by heat or a light breeze. But the moist haze, driven in by westerly winds from the sea, tends to linger and is only dispersed by strong winds. In the eastern part of the Channel, it is rare for the land to be completely free from mists. The only exception is when the wind is from the northeast which makes the mist free coastline highly distinctive from a great distance.

With thanks to:

Micheal Harpur eOceanic.