Round the Island - walking the course

In part one of this series leading navigator/tactician Mike Broughton takes us to the Needles

General Information:
HW Portsmouth is 0727 BST - Neaps
Pilotage books: Solent Hazards and White Hazards by Peter Bruce
Tidal Information: Solent Tides by Peter Bruce
Solent and Isle of Wight Tidal Streams by 'Check Charts' (half hourly tidal streams)


First Quarter - Start to the Needles distance approx 13nms

Initial Strategy - Plan to aim for Sconce buoy where you can make the most of the 'tidal slingshot' just to the west of Yarmouth. Then continue in the fast moving current towards Hurst Castle, then if you are beating into the prevailing southwesterly winds, work the area of best current close to the Shingles, prior to peeling off and aiming for the Needles.

A Bit of Geometry -The actual start line is 1.2 nm long (from the Royal Yacht Squadron (RYS) to West Bramble). In simple geometry terms, the shortest distance to Sconce is the perpendicular (rhumb line) to the buoy and is not in the middle of the line, but just a quarter of the distance up the line from the RYS. Starting close to West Bramble is a whole 200m further than at the perpendicular point. There are often good reasons to start elsewhere, depending on the wind, tide and the main body of the fleet, but always remember that extra 200m if you are aiming for Sconce and starting near West Bramble buoy.

Osbourne Court Top Window - The RYS start line transits and high intensity lights are never more difficult to see than on the RTI Race in the final 25 seconds to the start gun, as they invariably get obscured by other boats. Brief your bowman to also be aware of the transit of the RYS Flag Staff, in line with the top window in the tower of Osbourne Court apartments. This transit is usually visible above the height of other boat masts.

The Best Tidal Stream - For those starting between 0800 and 0900, the area of strongest tidal stream, will be around 300m north of the Cowes Green. Look in particular for 'Micky's Tidal River'. On the ebb, this is a local 'river of water' that looks brown and flows between 0.8 and 1.4 knots faster than the rest of the ebb. It is actually a layer of 'fresh water' that is usually only 400m across and sits on top of the more dense salt water. It runs west, just north of Gurnard buoy, prior to swinging over towards West Lepe Buoy and then swinging back towards Yarmouth and merging with the strong tide off Sconce. Note the local mini tidal race just inside Black Rock buoy, as the tide sluices round a mound on the seabed (don't hit Black Rock itself, 200m south of the buoy).

Continued on page 2...

Tomorrow Mike Broughton looks at the second quadrant of the course...