Modern High Aspect Keels Need Flow At All Times.


With the burgeoning Sportboat fleets and modern yacht design favouring high aspect keels, maintaining flow over the foils has become increasingly important.

To get a great start, line up slightly sprung sheets and hold your course until the boat is at full speed and then gently steer up to close-hauled just before the gun goes.

If you end up with a boat to leeward of you, still try to go straight while accelerating slightly lower than their angle. Even though you’re getting closer to the leeward boat initially, you’ll be generating better speed, grip and lift which in turn gives you more height and speed so you can lift off them.

Crews, but particularly helmspersons must constantly be on the lookout to avoid stalling the foils and must execute smooth turns and maintain boatspeed to stop that from happening.

At the leeward mark start your turn when you’re around 2.5 boat lengths abeam of the mark, this assumes that traffic will allow this.  Do that and you’ll have way more grip on your keel and end up in a higher lane than boats still turning as they pass the mark, that’s when the keel stalls and the boat slides sideways.

It’s OK if your arc takes you a little downwind of the mark before turning up. Again, the idea is that, as you finish the turn and actually pass the mark, you are already close-hauled.

Ducking a boat upwind requires the same consideration. The penalty you pay for turning hard at the boat you’re ducking is greater in a sportsboat than in a fat-keeled boat, for the same reasons.

You’ll gain more by ­bearing away early, building speed, and doing a small head-up as you pass astern of the boat you’re ducking.

If you constantly pinch, your VMG will be worse with a skinny keel because you’re close to stalling the keel all the time, and the boat needs more flow to create lift.

Try adding a couple of tenths to your boatspeed by initially steering down a degree or two and you will almost always end up pointing as high as everyone else because you have way more flow over your blades.

A word of caution though, you can overdo it and start reaching around the course, but pinching on a skinny keelboat is far worse.







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