EPS and Polyurethane Constructions

EPS & POLYURETHANE Constructions

Hydrodynamica Test Pilot Series planing hulls are available in EPS foam with epoxy resin or polyurethane foam with polyurethane resin.

Most of the project boards have been EPS foam with epoxy. This is to acknowledge Simmons’s early work with Styrofoam and for the lightness, buoyancy and performance characteristics this foam provides. EPS enhances the planing and paddling performance of the boards through buoyancy by keeping them up on the surface of the water.

Conventional polyurethane performance is excellent as well, giving more of an “old school” ride and helping the board to penetrate the surface in carves and turns. Polyurethane resins can take all the traditional resin tints with gloss and polish for those who want a classic look.

The choice between EPS and Polyurethane is really up to the rider.

Comparison of palning hull design and typical modern boards Comparison of palning hull design and typical modern boards

White line = conventional shortboard. Black line = planing hull.
Note the increased area and flatter bottom of the planing hull as compared to a conventional shortboard of the same length.

Planing Hull vs. Modern Shortboard

The planing hull is a high aspect ratio design. When compared to conventional surfboards the planing hull is wider, shorter, much flatter, and has a more parallel outline.

The front third of a planing hull is a wide, rounded spoon that is lifted with camber before it blends into the planing surface of the back two thirds. The rails are round and neutral giving way to a hard edge in the tail, which ends with a 10” minimum width for clean wakes and minimal drag. Fins are set as far out on the rail as possible to maximize planing surface and give the board directional stability and drive. Many of the Test Pilot Series boards have wings where the front fins are set for maximum width before the tail tapers to the 10” minimum.

Conventional boards use rocker, outline curve, and a fin cluster that causes them to be maneuverable from a sweet spot on the tail. Planing speed and trim are sacrificed to achieve this.

The planing hull turns off its rails without sacrificing planing speed and trim, two of the most pleasurable aspects of surfing. Since planing hulls can be surfed very short, with a minimal rail line, radical turns, floaters, and aerials are still possible. That being said, planing hulls are more oriented towards fast, horizontal, carve based surfing than they are for vertical turns in the lip.

What to Expect


Planing hulls are excellent boards for beginners during their first or second year of surfing. They paddle extremely well and are far more stable and forgiving than other boards, especially shortboards. Their buoyancy and quick planing speed help familiarize novice surfers with trim, planing, and basic maneuvers like climbing and dropping, bottom turns and cutbacks.


Intermediate surfers will find a whole new world of speed with the planing hull. Sections that were previously un-makeable on other boards can be floated over or traversed with ease. Wave count goes way up compared to conventional boards. Fun quotient goes through the roof.


The speed generated on short planing hulls is a unique thrill, with aerials, 360° rotations, and controlled slides all part of the mix. The planing hull offers rail-to-rail surfing as compared to the more tail-oriented surfing of a typical shortboard. For relaxing, having fun, and experiencing new sensations, the planing hull has plenty to offer experienced surfers.

The Mini-Simmons

Planing Hull Dual Keel

The Mini-Simmons

The Mini-Simmons has brought Simmons to life for an entire generation of surfers more than five decades after his death.

The Simster

Planing Hull Tri Fin

The Simster

The Simster was inspired by Simmons’ attempt to build Bev Morgan a short, tri-finned planing hull nearly sixty years ago.

The Fourke

Planing Hull Quad

The Fourke

The Fourke features a quad keel set up with single foil Gephart front keels backed with basey double foil trailing fins.

The Ekstrom

Planing Hull Asymmetric

The Ekstrom

Carl Ekstrom innovated the asymmetric surfboard in the mid Sixties. Asymmetry helps loosen the heel side rail of a planing.