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)
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.
Thought that would be the case. Bugga!! Always after an easy fix but gotta work on that technique.
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
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.
I remember reading that fin size should roughly equal sail size times 5, plus 2. Then you add 1 or 2 cm for larger board (over 110l), heavy sailor or light wind, or subtract 1 or 2 cm for the opposite - eg smaller board, light sailor, or strong wind.
Seems to work as a rule of thumb but there's always exceptions.
Some brands of fins have better foils and don't spin out as much as fins with bad foils or chipped scratched surfaces. Bottom board shape can also make a difference eg a single concave bottom can channel more air to around the fin.
A lighter person uses a smaller fin and vice versa.
