Finologist Larry Allison Explains 4 Fin Race Twin Layout on a Raceboard

Why does my Paddleboard only have 1 fin??

My name is Marc and I like to think of myself as a Surfer,,,,,, I have a quiver of boards and except for my current longboard all of my other boards have multiple fin options yet my 14′ SUP raceboard has 1 fin and no expansion options for different conditions so I’m confused.

If you asked me if I wanted to go Surfing or Paddleboarding I’d say Surfing then Surfing, then tacos, and then a paddle. It’s simple for me –  the adrenaline rush of getting on a wave on a surfboard can’t be duplicated. As a Surfer I have a better than decent knowledge of how fins work and what works best in different conditions and what setup I like for different boards in the quiver. If you Surf you totally understand that changing the fin setup on your board can completely change the performance. Paddleboarders for some reason don’t seem to understand that the same fin principals are at work on their Paddleboards. They buy a board and off they go.

Think about it – most surfboards made now have 5 fin setups standard so you can run your stick as a single fin, twin fin, quad, thruster, or 5 fin. If the changes from one setup to another didn’t make a difference they wouldn’t make boards with multiple setup options? Go buy just about any Paddleboard like I did and you have 1 fin and only 1 fin option. Wait, what 1 fin? I mean my Paddleboard is 14′ and I ride between a 5’7 and 6’0 surfboard and I can run 5 combos and up to 5 fins at a time??? Yes, yes, yes, I only use 2 combinations, (either thruster or quad) but their is a big difference between the two on how the board reacts. It appears to be obvious that additional fins on a Paddleboard would change even the basic dynamics of the board. a dorsal fin should help with side rollers and current right? Adding a twin setup at the rear should help propulsion right? What about a quad setup? I mean it does work on my surfboard.

After seeing the 4 fin setup on a few SUP race boards I asked around and was told that I should give the “Finologist” Larry a Call.

So I sent Larry a DM on IG, (cause I’m current on tec.). Larry responded and told me to give him a call. I called and told him who I was and what I did and then we spent about an hour on the phone while Larry explained everything about the 4 fin / ProBox setup. It was eyeopening and confirmed my initial thought that Paddleboards should have more fins and more importantly why.

If you don’t know Larry and you like to Paddleboard or better yet RACE your paddleboard you need to get on board with what he is saying and how he is changing the way race boards perform.

Here is our take: Larry is the foremost and “OG” Finologist in the world. Larry also makes some of the most badass SUP fins that one can buy and we’ll be reviewing his fin line in future posts.

Here’s a taste of some of his fins: they can be purchased at local retailers or go to and select LAFins

Get Larry on the phone for 2 min and you’ll know Larry is the real real. A 5 min conversation with Larry and your mind will be obsessed with thoughts of changing your race board to a ProBox setup. A 10 min conversation and you’ll be asking for his address to ship your board to him for a retro fit without ever asking or thinking about the cost, which is very reasonable BTW.

I’d bet that more than likely if you did get him on the phone you’ll spend an hour with him while he gives you the master class in “Finology” and this won’t be your typical 101 level class we’re talking the PHD level class so pay attention people. Their won’t be a test after you get schooled but if you fail to pay attention you’ll keep finishing at the back of your age group at the next races.

Some of Larrys handy work:

So here at we don’t have a team of internet fin historians and fact checkers to check this next statement for accuracy but at we believe that Larry is the OG and creator of the ProBox system or in layman terms putting 4 fins on a Paddleboard. If we’re wrong whatever but we’re not wrong that he has perfected the system. Yes the setup has been copied by others that chose not to work with Larry and they will tell you that their setup is “better” and have a good marketing statement to go along with it.  The reality is that other stock 4 fin setups aren’t as good as they have made slight changes to critical measurements to call it their own and slight changes in measurements has big effects on performance.

If Larry did the retrofit on a board or he gave someone the template using his measurements then his setup is better than others. (period).

Here’s a video of Larry explaining the 4 fin race twin layout:

If you race your paddleboard get in touch with Larry about getting your board outfitted with the ProBox system he is the OG, PHD Jedi master of the setup.

You can checkout the system at:


You can stalk Larry here:

@lafins Instagram





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