What fins do you use?

Do you use side fins with with concave inside foils or the traditional flat.

If you have a preference why?

I’m trying both atm and am not really sure if there is a noticeable difference or not.

I have always used the traditional flat.  Last year I ordered an expensive set of fins with the convex inside foils as you call them.  They’ve now been ridden in three different boards and they humm like crazy in all three boards.  The edges are all clean so the only conclusion I can come to is that it is the cupped inside foil creating the problem.  Complete garbage.  When I would pump down the line I swear they sounded like a flying saucer in an old Sci-Fi flick.  They had been sitting on a shelf after only a couple sessions of use.

Yesterday I put them in my 14 year old grom’s new board.  He thinks they’re cool because of the fancy looking carbon fiber but he didn’t know about the humming issue I’d had with them.  We had solid waves yesterday…probably close to double overhead on my 14 year old.  After a couple of waves he paddled over to me raving about his new board but complaining that the fins were humming.  I was actually surprised that a 100 pound 14 year old could get them to humm.  I told him we could put regular fins in his board but he wants to keep them because they look cool.  No way I could tolerate that humming…he can have them.

The inside foils don’t always hum, that’s too bad you got a bum set. Usually the hum comes from a too-thick trailing edge, so you might try sanding that a bit.

General rule is flat insides for powerful or large conditions and cupped insides for everyday or mushy waves.

Mike, that’s the sort of rule-of-thumb I was after. Based on not-much-at-all I had guessed the opposite, that the flats would be better in smaller or less powerful conditions

Mako, funnily enough, a pair of my flats were humming badly this morning. I had de-sharpened the trailing edge with some 500 then 1000 grit wet and dry, as I usually do, but as Mike said that may be the cause as they are otherwise in perfect condition

I use my own G10 fins.

I wonder how hard it would be to shape an inside foiled set…


It’s not too hard to do an inside foil, especially in an easy-to-foil material like G10. Just stick the nose of your disc or pad in there and get after it!

What I said about suitability for conditions is sort of a consensus of a lot of rider opinions and talking to fin guys. There’s always exceptions, fins are another place where personal preference and how YOU surf come into play.

home made ones … whatever the imagination and limited skill level  allows



Good Ben. How’s Vic, there should be enough surf and the associated surf scene to keep you occupied. I’ve stopped working and am spending most of this year in Indonesia. I’ve been staying around Uluwatu and will move further afield once the dry season gets underway.

By the way my favourite centre fin is a Curtis hatchet fin with a very unusual foil. It provides that magic hold with extreme looseness. Trouble is its for a Future fin box and all but one of my 9 boards are FCS.

Take care Ben

Hey everyone, I’ve been using the Futures’ Solus fins. I have a bunch of fins, but these ones are my favorite. The center fin is a slight hatchet that really thickens up towards the tip so it always feels like it has a really nice pivot. The side fins are foiled on the inside and I feel like they’re a perfect combination of speed, control, and loosness. Overall very balanced fins. I think you have to order them online though, the weird shape I would assume makes them not the most popular choice for people who don’t want anything “weird”. I prefer futures over FCS just because they’ve had the least problems in boards I’ve ridden and I like the options. Here’s a picture of the fins.


Krystian, that’s the style of centre fin I was referring to, although the one I have is a more extreme version.

The ‘arm’ of the fin is much more narrow and has thinner foil than the head of the fin. The head has a round blunt leading edge nearly 0.5" thick. There is a raised shoulder where the arm meets the head.

Design is obvious: narrow base loosens the fin up, bigger area head stays deep in the water away from the turbulence at the base, blunt leading edge does not stall at a high angle attack. The result is loose with hold but still reasonable drive.