Mike Broughton's Cowes Week nav tips

Former Whitbread navigator and Cowes veteran Mike Broughton gives his top tips for winning this week

Can I get over the Brambles? -Tidal Heights made easy. A great short cut for working out the height of tide in the area of the Brambles is to use the first class Roberts Tidal Slide. On the front it has the tidal flow for the area in fine detail, then on the reverse are the predicted tidal levels for both mean springs and mean neaps. This is an easy and quick method, rather than doing a three way interpolation between three secondary ports! To make things even simpler, I like to transfer these heights to the corner of my plastic chart using chinagraph, enabling me to come up with a tidal height very quickly in the heat of the battle.

Height of tide at the Brambles using HW Portsmouth
1020 - 5 1.7
1120 - 4 2.0
1220 - 3 2.5
1320 - 2 3.1
1420 - 1 3.7
1520 HW 4.1
1620 + 1 4.0

Instrument Calibration. Instruments are expensive but of little use if not calibrated. Don't settle for large errors and always check out the wind instruments at the start of each day. After a while it is quite possible to refine the errors for particular wind strength down to one or two degrees. For years I always had to double check which way I had to make the correction. These days I use a simple mnemonic, which I never forget:
H on P + (decoded means High figures on Port Tack, add).

' Broughton on the Brambles' - fortunately only once, while mast tuning on a quiet Friday evening, but once too often! The Brambles Bank has a huge influence on racing in the Solent, so get to grips with where it actually is. These photographs while only a little out of date show the Brambles to be a different shape to any charts published before 2000. Made up of stones and shingles, there is a definite arrowhead facing the flood tide. The beacon has a depth of 4.5m at MLWS. There are a number of transits to fix the edges of the bank. The simple one I like is the one that defines the eastern edge (the back of the arrowhead): use the transit of the Brambles beacon in line with the tall chimneys at East Cowes (they appear as one). The transit runs north/south, so if you are to the east of that transit you are clear of the bank. Despite the puddles, the bank is very flat and dries to one metre at Chart Datum. When sailing in this area, beware of Knoll Bank to the east, which only has a depth of 0.9 m at Chart Datum.

Always have a Hand Bearing Compass. Check that your hand bearer correlates to the main and electronic compasses. It then allows you to compare like with like, when one is used for the start line and the other for the wind direction, when deciding how much bias there is on the line. Also use the hand bearer to monitor the opposition as well as to 'shoot up' the next mark (look along the bearing). A notebook or wet notes are an essential item and have a myriad of uses. I always like to draw up a matrix prior to racing, so that I am not scrabbling around to scribble the course down on the front cover of the Sailing Instructions at the ten-minute gun. This also allows me to follow any subsequent course changes logically. One useful trick after racing, which saves much time searching the following morning, is to tie together the hand bearer’, handheld GPS and the handheld VHF before you stow them!