The proprietors of the Below The Boat store are adamant that they sell carved charts, not carved maps. They're correct. Underwater terrain is shown in a bathymetric chart not a topographic map. Cartography jargon aside, we're still pretty excited about these charts, designed and crafted overseas by a small family-run operation.
The content very much fits the medium. The original bathymetric charts that these pieces are based on have an extremely simple composition: usually just thin black lines on white paper, sometimes with a little blue shading for bodies of water. In this carved version, the precision of the original lines translates to the laser-cut wood forms, and the layering of the thin wood adds another dimension to an image that was, after all, designed to represent depth.
We can vouch for the wooden charts as navigation tools. Rather, Below The Boat sells them with a dark wood frame for wall hanging. You can see if your favorite body of water is currently for sale over at their online store.