The trend used to be weight plus 10L , is that still what people do now with multi fin boards?
Suppose it depends on where you are sailing and what kind of sailing you do.
When I was in Tassie I weighted 80kg and used 70L because it was always so windy, Came to margs and all I did was dredge the bottom of the ocean, ended up on an 83L after a couple of years, then I got fat 90KG and usually ride a 94L.
Cool story hey.
But I reckon use a big enough board to suit your conditions, but small enough that it still feels nice on the wave. If you can't get a rail in, it's probably to big for you. or the volume distribution is all wrong.
Busy work day
Select to expand quotecurac said..
Suppose it depends on where you are sailing and what kind of sailing you do.
When I was in Tassie I weighted 80kg and used 70L because it was always so windy, Came to margs and all I did was dredge the bottom of the ocean, ended up on an 83L after a couple of years, then I got fat 90KG and usually ride a 94L.
Cool story hey.
But I reckon use a big enough board to suit your conditions, but small enough that it still feels nice on the wave. If you can't get a rail in, it's probably to big for you. or the volume distribution is all wrong.
Busy work day
Suit the conditions being key.
curac...liked your short story, are you still 'large' 
Back to topic another point is enjoying the conditions as best you can and having more volume
means possibly having 0.5m less sail. For east coast of NSW you'll see 75-86 lt for the smaller
/skinny guys and easy 88 lt plus for the 85kg + blokes.
I think the 100 lt + boards start getting too wide to be decent on the waves - opinion only!
