NavList:

Bob

Thanks for the derivation. That'll do me to experiment with.

And your example results summarise as an approximate rule of thumb, invoking the Beaufort scale to produce a memorable pattern:-

4kts       F1      40 degrees off

8kts       F2      30 degrees off

12kts     F3      20 degrees off

16kts     F4      10 degrees off

I try to keep my boat as light and simple as possible, no wind indicator, no computer optimisation, so that's enough for me to experiment with.

See you on the (usually short) (usually single handed) race course, I'll be looking everywhere except down.

Good sailing, and thanks again

Michael Bradley