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Thought for the day - Is your boat gradually losing its performance edge

After sailing last week, I got into a discussion on the ageing of boats and the effect on performance. IOM's are low stress boats and the hulls should last for a very long time. However the rigging and setup can change very quickly and lead to a gradual deterioration in performance. Lines can stretch affecting rake, sheet angles and rig tension. The prebend in the A rig can gradually reduce leading to less control on the jib, hence why I made my own prebend device

One of my thoughts for the day shows my home made prebend machine and I will be keeping an eye on the amount of bend from week to week. Pleased to say the B rig has maintained its prebend but it has not been used much.

If your boat is lacking an edge, try tuning up the engine of the boat with some or all of the following.

Check all your settings

As a minimum you should measure mast rake, usually from the top of the bow inside the bumper, to a fixed point on the mast as well as the distance of the main and jib booms from the centreline for sailing upwind

If you do not measure, these the setting can creep over time.

Watch for a reduction in Pre-Bend

5mm less prebend reduces jib luff tension, opens the jib leach too much in gusts and reduces acceleration. I have seen and recorded this on my own boat. Put the prebend back in, 15mm is the standard..


Lines stretch or shrink and yes that can influence performance. The ties holding the main to the mast can shrink affecting the luff curve of the sail. Sheets can stretch. A couple of mm here and there can make a big difference when sailing to windward. Replace lines when they start to look worn or bleached and ensuring the mast rake and sheet settings are maintained. I can see now why Lester Gilbert went into so much detail on boat settings on his web site.


If your sails are beginning to look tired, buy a new set. They can cost anywhere between £60 and £100+ per rig and have found the £60 variety perfectly adequate for club and serious sailing. Spend a little bit more and you get that marginal gain.

Finally some thoughts on how you sail.

When sailing to windward, do you try and point high. More often than not sailing a little freer not only makes you faster but in the end you will point as high if not higher because the fin will provide some lift with the extra speed.

If someone ahead get a header in front of you, crack off and drive into it or tack. A momentary header where your jib starts to back kills speed.

Is your boat balanced to windward? If it is you can look up the pond for the next big shift while your boat steers itself.

Do you use tell tales and a burgee. I always used these on a dinghy and yacht however large and cannot sail without them on an IOM. They are your eyes and ears on the boat especially in fluky conditions.

Do an audit on your boat and sailing round a race course. Have a friend watch you and get feedback. We might not like what they say but it will make us faster. No pain without gain as they say.

Good luck to all

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