# Laser cutting a bathymetric depth map > the lake-house classic: stacked depth bands cut from wood or blue acrylic 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](/map-designer?preset=lake-depth-chart) is the purpose-built starting point; the same technique drives the [Coastal Depth Chart](/map-designer?preset=coastal-depth-chart) for sea floors and the [Land and Sea Relief Map](/map-designer?preset=land-sea-relief-map) when you want mountains around the water too. ## What you need ### Materials - 6 sheets of 3 mm [laser-grade plywood](https://yxecreations.com/collections/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](https://yxecreations.com/pages/acrylic-sheets) for the bands if you want the color to do the work - no painting - Glue or [3M tape](https://yxecreations.com/collections/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](/map-designer?preset=lake-depth-chart). 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. ## Laser Cutting & Engraving ### Cut and assemble the stack 1. Cut the **Backplate** from your darkest material first. 2. 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. 3. Cut the **Shore plate** last from your cleanest sheet; it is the face everyone sees. 4. Dry-fit bottom-up: backplate, band 5, 4, 3, 2, 1, shore plate. Check it against the on-screen chart before any glue. 5. 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](https://yxecreations.com/collections/3m-tape) 300LSE (or 467/468 for acrylic) skips the drying time. 6. 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. ## 3D Printing ### If you would rather print it 1. Export the 3MF - shore, the five teal bands, and the navy floor arrive pre-colored for a multicolor printer. 2. Single extruder: print the STL in white and flood the basin with thinned blue acrylics, darkest at the bottom. 3. Print flat, no supports, 0.16 mm layers for crisp depth steps; 180 mm+ preserves narrow bays. ## 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: https://www.mylasertools.com/map-designer?preset=lake-depth-chart Read online: https://www.mylasertools.com/learn/guides/laser-cutting-bathymetry-maps