I think technique plays a huge part on spin outs. If it was all down to fin size compared to weight the guys sailing around on 14cm freestyle fins on 100lt boards would only ever be able to go downwind. 23cm sounds about right for a starting point on a 78lt. A 24cm fin came with my 75lt and I replaced it with a more DTL 21cm wave fin because the 24cm was too big. never had spinout problems from it being to small though and I weigh 75kg.

and possibly harness line placement to balance you and rig better. I had mine a little to forward meaning I was reefing in with the rear arm and loading my back foot up then spinout

waggles56 said...

Does a persons weight effect the recommended fin size? E.g a 78 litre board that sells with a 23cm fin will suit the Mr Average 80kgs.
What if you weigh 65kgs or 105kgs. Does the lighter person still usually use the 23cm fin (in the same conditions and sail size), or should they go longer or shorter.
Just wondering as I spin out a lot on my new board and was wondering if it was my technique or I need a longer fin. (I weigh 68kgs)

What size sail are you using for your 23cm fin?

I find that on my 80 litre board, a 25cm works with a 6.0, a 23cm works with a 5.0 and 4.5. (well it did when I was 85 kg, haven't tried it lately...)

I'm guessing that if you're lighter than the norm then you could get away with a smaller fin, because you won't be able to get as much force from the sail. As others have said, as you get better you don't need as much fin -- but when you're a hack like me it's nice to have a good solid fin to stomp on.

sboardcrazy said...

I noticed that after I bought a larger board 125ltres & didnt use a small board for almost a year ( due to no wind) I had a lot of trouble with rounding up & other things because I'd got used to the forgiving big board .I needed to tune and get used to a smaller one again.

Probably the case with me. Coming from a 101 litre to 78 and only used it twice. I think I will move the harness back a bit and keep going with the 23cm fin. Sounds like I just need to focus on not loading up that back foot.
Was using a 5.4 sail last time out but in overpowered conditions.