The logo is based on one of my favorite technical illustrations, taken from the classic work from the 1950s, Hydrodynamics in Ship Design by Harold Saunders.

The drawing resolves the "Froude paradox," demonstrating why surfing is possible even though local gravity and acceleration-induced body forces on the surface of a wave always resolve to a direction normal to the local wave surface.

The drawing also shows why surfing is possible for a fully submerged object with approximately neutral buoyancy.