Hello, I'm new to the sport and I'm building a twin-tip plyboard that will be about 4 ft long and around 20 inches wide. I'm just curious if I should put fins on it or not as a lot of newer designs are finless. I come from a snowboarding/ windsurfing background.

hi, first off, 20" is probably way too wide of too wide. Try 16" max for a 4' board.

Where fins help you is tracking the board. So, if you're not going to use fins then think about a degree of concave edge on the tip and tail. As you have a wide board you've got planing you dont want a convex rounded tip and tail as this will make the board too skatey and give the sensation that the board has no ballance point.

Another thing you could consider is a stepped rail. Say about 8" from the end you bring the rail in an inch and then continue with the rail for about 3" then shape the end of the board - make it squarish. Shape the rail down and the step & end up. What this little step does is act like a fin when your on the edge, it also gives you a shorter rail overall for the board which really helps in overpowered situations. Disadvantages is that you dont have the most efficient board and its hard to get the proportions exactly right.

hope this helps

Thank you for replying. The board actually ended up being 15.5 inches wide and 4 feet long. It's probably a bit short for learning, but I might be able to borrow a board from a friend while learning. I used squared off tips and it pulls in a bit at the tips. the tips are about ten inches wide. It also has an inch and a half of rocker with a flat section in the center. I hope it works well. I think I will use fins since I am a beginner. Thank you for your assistance though. I will use it on my next board.

thats the dimensions of the boards I make at the moment. Its a good size and you will be able to ride it no problem. From what you describe it sounds like a good design. You can get cheap fins from a place in south africa.. http://www.dovetechaquasport.com/ they're ok but dirt cheap and can take a little time to arrive but you get 4 for something like $8

good luck