Sailing Downwind

Downwind always known to be slower than a broad reach. If you can do 4kts dead run, you can probably do 5 on broad reach.

If you had a 1nm leg, doing 4kts you will complete in 15 minutes.
Let's say you go 30degrees off the wind angle at 5kts would be less than 14mins if my maths is right

Your maths is correct but there isn't much in it. By sailing 30 deg off DDW you will sail 115% of the distance. If your boat will sail at 120% of its DDW speed then, yes, it is faster to head up. But will it? I guess if it were cut and dried we wouldn't be having this conversation. Nick Craig says 'soak if you can but during your practice sessions experiment with other angles' if I remember correctly

Forgetting the asymmetric issues you raised...they're different from a Phantom. And unstayed rigs like Lasers who do the reverse flow. The stays on a Phantom make that difficult. There are 4 reasons for gybing downwind (1) clearing your breeze from other boats (2) tactical (to gain a ROW advantage or escape from somebody elses), (3) to head towards better breeze, and (4) to point more towards the leeward mark (windshifts).Those are the main things. In a busy fleet 1 and 2 might be unavoidable. But when those aren't so much of an issue , 3 (in patchy breeze) and 4 (in a shifty breeze) are what you should always be trying to deal with. But you should always be trying to do 4. To be doing 4 well, there will be a sweet spot, where your sail is generating max drive whilst trying to go as low as possible. That's the struggle, it’s a feel thing and will only come from racing your boat frequently. But as others have said, a good thing would be to talk to people who are good at sailing Phantoms. I think there's a few good Phantom sailors on here.

Originally posted by Wetabix Your maths is correct but there isn't much in it. By sailing 30 deg off DDW you will sail 115% of the distance. If your boat will sail at 120% of its DDW speed then, yes, it is faster to head up. But will it? I guess if it were cut and dried we wouldn't be having this conversation. Nick Craig says 'soak if you can but during your practice sessions experiment with other angles' if I remember correctly

Pretty sure this is the art of racing. Knowing do you go 5, 10, 15, 29, 30 degrees for the conditions. Plus Reading the shifts and the conditions.

You only need to get a boat length ahead for things to matter.

My example was picked for simplicity of maths.

Polar plot from a Volvo Ocean 60


Not the perecntage difference changes by wind speed.

Not sure what matters?

Get three identical boats to round a windward mark in quick succession. Boat 1 - dead down wind. Boat 2 - 10degree, Boat 3 - 30 degree...

Who hits the downwind mark first...?

This is why good racers practice. They are testing different approaches

Originally posted by polc1410 Originally posted by Rupert On a pond for 100 yards I'd bet on the straight line. If they can gybe efficiently... the guy who goes 10-15 degrees may be very pleased by your decision ;-)

Maybe, and sometimes I'll bet against, with, as you'd expect, mixed results, some good, some bad.

But putting this into a racing situation means my decision to go off course will be influenced by everything others have said. If someone is sailing angles, I may decide to cover and keep clear wind. If on my own, then the choice is DDW or 5 degrees off to create flow, depending upon wind strength, where the trees are, etc, as JimC says.

But I sail short, slow boats, so the speed gains are limited, especially in non planing conditions.

Volvo 60s they are not.