WG2 fin for longboards and SUP - Wavegrinder

Fin Sciences


The WG2 fin for longboards and SUP is our latest fin, designed for excellent turning and speed. Our fins with winglets produce a lot of hold and drive (lift–see article), so we can make them smaller than the average fin–by 20 to 30 percent.  Basically we take a “regular” fin, chop off about 30 percent of its area, then add back in about 5 percent in the form of winglets–just like what airplane designers do with airplane wings these days.  The result is a fin that produces the same amount of hold and drive (aka lift–see post) as other fins, but with a smaller surface area.

Because our fins are smaller–they have less surface area–they have less drag.  And less drag means quicker acceleration, easier paddling, and longer sessions. These fins  don’t stall like a typical fin–because of the foil section we chose.

Less drag, more fun! Faster fin, better acceleration, better turning, longer sessions! That’s what these fins are about!

Like our Wavegrinder Classic fin, the new WG2 fin is just over 30 square inches.  We moved the winglets to the end of the fin to increase overall performance.  We decreased the size of the winglets a bit to decrease drag even more.  And we added a bit more sweepback, or rake, to help shed kelp, while still maintaining a very high aspect ratio and low taper ratio–in other words, it provides excellent hold, good drive, accelerates quickly, and paddles easily.

  • Ever miss that perfect wave by half a stroke?  If your fin had less drag,  you’d have caught it!
  • Ever lose a wave to somebody who paddled in just a bit faster than you?  If you’d been able to accelerate faster, it would have been yourwave!
  • Ever feel like conditions are great, but you’ve been out so long your arms have turned into limp spaghetti noodles?  With less drag, you would have lasted longer and caught more waves!
  • Ever make a sharp cutback, or even a sharp right or left when trying to catch a wave, only to stall out and lose it?  A better turning fin that doesn’t stall so easily would help.
  • Ever wish you could ride the small waves in marginal conditions?  Less drag makes it easier to catch them!
  • Ever wish you could go faster to get to part of a wave that looks a little better?  A faster fin would make it happen!

Winglets have been used on aircraft for quite awhile now, people are used to seeing them on the end of airplane wings. But winglets also are used on submarines, on some rotor blades, on the ends of race car spoilers or air dams, and on boat keels. Winglets, or a version of them, were conceived decades ago, but not put into use until after Richard Whitcomb of NASA and Boeing studied their ability to reduce fuel costs by decreasing induced drag. Whitcomb found that winglets reduce induced drag by about 20 percent, while improving the lift-to-drag ratio by about 6 percent, findings that Boeing confirmed.

his Wavegrinder 2 fin for longboards and SUP has several features designed to maximize fin efficiency.

  • A high-aspect-ratio shape (tall and thin)
  • A low taper ratio
  • A short base
  • A cutaway
  • A bulbous forefoot
  • A NACA double-zero foil section
  • Winglets


  • Height/depth:  9 inches
  • Total area (with winglets): 30.6 sq. inches
  • Planform area alone: 28.5 sq. inches
  • Winglets surface area: 1.6 sq. inches (about the size of a US quarter)
  • Rake/sweepback angle: 15 degrees
  • Fits Fins Unlimited and Bahne Boxes

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