Rusty The What? Grom High Performance Grom Surfboard

A deep single concave with the deepest part in the entry, approximately 1/4 to 1/3 back from the tip of the nose, starts to shallow out through the center of the board and turns into a “hooked” double concave as it approaches the rear foot, coming into the front fins. The deepest part of this double con is under the rear of the front fin. The deep concave in the front creates lift. It feeds water back through the midsection and into “the zone” between the feet, generating a great deal of speed and drive.

A single concave helps to direct water flow, but it doesn’t really focus it. A double creates a lateral break and helps to initiate turns. It helps to focus the water through the fins. By deepening the concave and focusing it close to the rail, deepest under the front fins, it gives extra hold and provides additional thrust and drive.

The bottom finishes with a slight vee off the last few inches of the board. That helps to finish turns, smooth and connected.