Longboard fin-box guidelines? Some SUP/fin-brands with better fit?

Hi,

I wanted a recreational racer, and last year I got a good deal on a 2015 NSP Coco Race VC 14'.

The deep race-like fin was ok for flat water and less windy conditions. But I also wanted a shorter fin better for sessions with side-wind, hopefully also better for maneuvering during downwinders in light conditions. I will buy a more or less dedicated downwinder board in a while, but for now I want to fix a fin fitting issue and keep this mostly good board for the family.

I tried to buy an extra fin when taking the board out of the shop. The dealer agreed with me that the ones he had simply didn't fit well with the fin box, not nearly flush with the bottom of the board. So he recommended me to order one on my own. The original 12" deep race fin was flush, tight and just fine.

I made a note to order one during the winter, and totally forgot this issue until I received my chosen (discounted) FCS Fluid Foils Ezi Trim 8.5.

Same story, the base of the fin is a little more than 3 millimeters outside the board.

The distance, from the the rail-securing pin, to the blade (or the supposed board bottom line), is 11mm with the NSP and 14mm with the FCS.

While trying to find who is "right", I realize there's no disclosed attempt on drawing a standard.

Found nothing relevant searching stuff like longboard fin, US fin, box, dimensions, standard.

Si a little help would be much appreciated. I have no experience with other than the Futures and FCS proprietary systems on my kite- and surfboards.


Are such misfits totally negligible? Like, does the water-flow disregard this location?

Can I avoid this altogether in the future by choosing certain brands that seems to agree on dimensions? (can't even find where/if NSP is based on this planet)

Other brands with other box types? (probably not with racers/downwinders)



Thanks!

Fin fitting problems are an endless supply of frustration for SUP owners. It looks as if NSP themselves use at least two different fin boxes, so that fins that come with one NSP board might not for another NSP board. This is just DUMB IMO. Sort it out, NSP!

True Ames are great, and their service is very good. So I agree that it would be worth asking them about their fin base dimensions. They probably aren't going to know if their fins will fit an NSP SUP though. I doubt if NSP know either.

Now when buying a SUP I look carefully at whether the finbox is one of the standard sizes. If not, I give them a miss. Some SUPs have windsurf-type boxes which means that many surf fins don't fit well. It looks like some NSP boards might have these rather than standard US surf (FU-type) boxes like you generally find on eg. SIC, Surftech etc.

To add to the complication, even specialist SUP fin manufacturers produce fins that often don't fit big brands boards, and aren't always clear about which brands' boards they will fit. I have fins by e.g. Black Project and VMG that fit several of my boards very badly - in some cases so badly that I can't use them. This is despite researching it as carefully as I could before purchase, and in one case actually getting advice from the fin brand before buying (which turned out to be completely wrong).

The whole thing is a mess, basically. There are so many different standards, and retailers/distributors of either boards or fins rarely know which they are selling. Some brands seem to go completely off-piste altogether.

I guess it's another reason to go custom. You can get exactly what you want then. Plus the actual fitting is often better carried out too (which can affect fin fitting even if a standard box is used). The two finboxes I have (out of 17 boards I own) that fit the largest number of my fins best are the two custom fitted ones. It can save a lot of money and hassle in the long run.

Thanks all, for great help.
The FCS fin actually came with a pack of shim strips, although not the negative ones that I needed in this case!
Will try True Ames. Fins are not (yet) what's eating available gear storage space :)