Laser cutting a bathymetric depth map

Difficulty: Medium. Time: 2–3 hours including glue-up. The single most giftable laser-cut map you can make.

Bathymetry is the underwater half of a map: the shape of a lake or sea floor, drawn as depth contours the same way a topographic map draws elevation. Cut on a laser, those contours become the layered depth chart you see in lake houses and marinas - a shore plate on top, a ramp of teal bands stepping down through the water column, and a deep navy floor at the very bottom.

This guide is about getting that stack right on a laser cutter. The Lake Depth Chart preset is the purpose-built starting point; the same technique drives the Coastal Depth Chart for sea floors and the Land and Sea Relief Map when you want mountains around the water too.

Open the Lake Depth Chart preset

What You'll Need

Materials

6 sheets of 3 mm laser-grade plywood for a wood build (shore plate + five depth bands), plus one backplate sheet stained or painted deep navy
Or five shades of blue acrylic for the bands if you want the color to do the work - no painting
Glue or 3M tape (300LSE for wood, 467/468 for acrylic), weights, masking tape, a pencil

Tools

A CO2 or diode laser cutter and a flat surface for glue-up

Step 1 - Start from the preset and pick a lake

Open the Lake Depth Chart preset. It loads on Lake Tahoe at zoom ~9.8 with the whole lake in a square frame. Search your water body and zoom so the entire shoreline fits with a margin of land around it (zoom 9-10 for big lakes, 11-13 for small ones).

Depth data matters here. When you add or open the lake-depth layer you can choose Simplified (a modeled approximation, available almost everywhere) or Advanced (real charted surveys, for a growing set of major lakes). Famous deep lakes carve best: Tahoe, Crater Lake (nearly concentric rings), the Great Lakes bays, Loch Ness. If the preview shows a flat lake with no rings, there is no usable data there - pick a better-surveyed basin.

Step 2 - Tune the depth bands

Three groups, top to bottom:

Shore plate - the land around the lake, water cut out as holes. Preview color #DDF3F1. This is the visible face of the piece.
Lake depth - the bathymetry, five bands from shallow #DDF3F1 through #B7E3E4, #8CCFD7, #5DB7CC to deep #2F96B6, each a plate with the deeper water removed so the bed steps down.
Backplate - #0E4C66 deep navy, the deepest point.

Heads-up for wood builds: band 1 shares its color with the shore plate, which is fine because they are different physical layers. More or fewer bands trade detail for height - five is the sweet spot for a readable stack that is not too tall.

Step 3 - Export for the laser

Export the per-layer SVG ZIP - one file per plate, in order.
Keep the inversion / holes toggle on so the depth bands export as stepped plates, not solid water shapes.
Turn on small-polygon cleanup: depth contours throw slivers along steep shores that are impossible to glue.
Add a Hanger hole ring if it will hang from a hook.

Choose Your Build Method

Cut and assemble the stack

Cut the Backplate from your darkest material first.
Cut the five Lake depth plates, deepest (band 5, smallest hole) to shallowest. Pencil the band number on the back of each as it comes off the bed - they nest and are easy to mix up.
Cut the Shore plate last from your cleanest sheet; it is the face everyone sees.
Dry-fit bottom-up: backplate, band 5, 4, 3, 2, 1, shore plate. Check it against the on-screen chart before any glue.
Glue bottom-up, weight the stack flat, then sand the outer edges flush in one pass so it reads as a solid carved block. 3M tape 300LSE (or 467/468 for acrylic) skips the drying time.
Finish with matte clear, or stain band edges before assembly if you cut everything from one wood.

Engraving option: before assembly, engrave the lake name, maximum depth, and surface elevation into the shore plate. A fine paint-fill in the engraving makes it pop against the wood.

Make It Yours

Swap the teal ramp for navy-to-ice: #0B2E4F, #15507E, #2E78A6, #6FA8C9, #B8D8E8 for a colder northern-lake feel.
Stain the shore plate walnut and leave the bands natural birch for the classic lake-house contrast.
Cut the bands from successively darker blue acrylics and skip painting entirely.
Add a heart icon over the family beach, cabin, or marina on the shore plate.
Pour clear epoxy over the assembled basin for a glassy, bar-top finish.
Ornament version: switch to a 100 mm circle export shape with a hanger ring.

Open the Lake Depth Chart preset

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