# Laser cutting an ocean floor relief map > the continental shelf and sea floor of any coast, island, or reef as a layered teal stack An ocean floor map is bathymetry pointed at the sea: the continental shelf, the drop-off, and the deep water around a coastline, drawn as depth contours and cut into a layered relief. It reads like a vintage nautical chart given physical height - shallow reef water on top, the shelf stepping down through teals, and the deep navy floor at the bottom. The [Coastal Depth Chart preset](/map-designer?preset=coastal-depth-chart) is built for exactly this, using real public ocean bathymetry so coverage is global. If you want the land above the waterline in the same piece - cliffs, headlands, an island's peak - reach for the [Land and Sea Relief Map](/map-designer?preset=land-sea-relief-map) instead, which carries the topography and the sea floor together. ## What you need ### Materials - 5 sheets of 3 mm [laser-grade plywood](https://yxecreations.com/collections/laser-grade-plywood) for the five depth bands, or five shades of blue [acrylic](https://yxecreations.com/pages/acrylic-sheets) to let color read the depth - 1 backplate sheet stained or painted deep navy (`#0A3F5E` in the preset) - Glue or [3M tape](https://yxecreations.com/collections/3m-tape), weights, masking tape, optional clear epoxy for a water finish ### Tools - A CO2 or diode laser cutter and a flat surface for glue-up ## Step 1 - Frame a coast with a real drop-off Open [the Coastal Depth Chart preset](/map-designer?preset=coastal-depth-chart). It loads on Australia at zoom ~4.2, the continent ringed by its surrounding seas. Search your coast and zoom so the shoreline and the water around it both fit with a margin. The key to a good ocean piece is choosing a spot with a real drop-off. Ocean bathymetry is coarse very close to shore, so pick an island, a bay, a reef, or a stretch of steep continental shelf where the depth actually changes - Hawaii, the Channel Islands, a Caribbean reef, a fjord mouth. If the preview shows flat water with no bands, the sea floor is too uniform there; nudge to a steeper coast. ## Step 2 - Tune the depth bands Two groups, top to bottom: - **Ocean depth** - bathymetry on the Ocean source with the water cut as holes, five bands from shallow `#CDEBEA` through `#9FD6DB`, `#6FBFCD`, `#3F9FBE` to deep `#1E6F96`. Each is a plate with the deeper water removed, so the sea floor steps down. Band 1 is the visible top face: the shallowest water at the shoreline. - **Backplate** - `#0A3F5E` deep navy, the deepest water. Unlike a lake chart there is no separate land shore plate here - the shoreline is simply the edge of band 1. If your scene includes a chunk of land you want to read as land rather than shallow water, add a solid land layer in a sand or stone tone on top, or switch to the Land and Sea Relief preset. ## Step 3 - Export for the laser - Export the **per-layer SVG ZIP** - one plate per band plus the backplate. - Keep the **inversion / holes** toggle on so each band exports as a stepped plate, not a solid water shape. - Turn on **small-polygon cleanup**: steep shelves throw slivers along the contours. - Add a **Hanger hole** ring if it will hang. ## Laser Cutting & Engraving ### Cut and assemble the sea floor 1. Cut the **Backplate** from your darkest material first - or use a deep teal so the deepest water glows. 2. Cut the five **Ocean depth** plates, deepest (band 5) to shallowest. Each is a full plate with a successively smaller hole; label the back of each as it comes off the bed. 3. Dry-fit bottom-up: backplate, band 5, 4, 3, 2, 1, checking against the on-screen chart. 4. Glue bottom-up, weight flat, and sand the outer edges flush so the stack reads as a solid block. [3M tape](https://yxecreations.com/collections/3m-tape) 300LSE for ply, 467/468 for acrylic. 5. Finish with matte clear. For the showpiece version, pour a thin layer of clear epoxy over the assembled basin so the stepped sea floor sits under glassy 'water'. ## 3D Printing ### If you would rather print it 1. Export the 3MF for a multicolor printer - the five teal bands and navy floor arrive pre-colored. 2. Single extruder: print the STL in white and wash the basin with thinned blue acrylics, darkest at the bottom. 3. Print flat, no supports, 0.16 mm layers; scale 180 mm+ so the shallow shelf band stays readable. ## Make it yours - Great subjects: Hawaii and its volcanic drop-offs, a Caribbean reef, the Channel Islands, a Norwegian fjord mouth, the Great Barrier Reef edge. - Cut the bands from successively darker blue acrylics so the color alone reads the depth, then top with poured epoxy. - Engrave the place name and a depth scale into a band or a separate caption plate. - Mark a dive site, a wreck, or a favorite snorkeling spot with a small icon on band 1. - Swap the teal ramp for a cold northern palette: `#0B2E4F` deep to `#B8D8E8` shallow. - Pair it with a coastal city map of the same shoreline for a land-and-sea diptych. --- Open the Coastal Depth Chart preset: https://www.mylasertools.com/map-designer?preset=coastal-depth-chart Read online: https://www.mylasertools.com/learn/guides/laser-cutting-ocean-floor-maps