3D dive site maps — explore the seafloor before you dive with Pelagic Echo³

Most divers plan from a two-dimensional map. A pin on a satellite image, maybe a hand-drawn sketch in a dive guide, a description that says "follow the wall east." You enter the water with a rough idea, and the site reveals itself as you go. Echo³ is Pelagic's interactive 3D dive site map — built from real bathymetric survey data, rendered in your browser before you ever gear up. You can orbit the reef, fly along the wall, read drop-offs from any angle, and tap anywhere on the terrain to get the exact depth at that point. It's the most detailed dive site information available before you enter the water. Know before you go. That's the only principle behind it.

Why a flat map isn't enough for dive planning

A 2D dive site map tells you where things are. It doesn't tell you what they look like, how steep the wall is, how far the sand flat extends before the reef starts, or whether a drop-off is a gradual slope or a sheer vertical face. For a sport where three-dimensional spatial awareness determines both safety and enjoyment, planning from a flat image is a significant constraint. The difference becomes obvious the first time you open a familiar site in Echo³. A dive you've done twenty times looks different when you can orbit the full underwater terrain, see the relationship between entry point and the first reef structure, and trace the exact path of a route through real space. You notice things a flat map obscures — the secondary drop-off behind the main wall, the sand gutter connecting two reef sections, the shallow platform that makes a good safety stop on the way back. For a site you've never dived, the value is even greater. Walking through an interactive 3D dive site map before your first dive at a new location is the closest thing to a local briefing you can get without actually knowing a local.

How the 3D dive site map works

The terrain in Echo³ isn't an approximation. It's built from NSW Government digital elevation and bathymetric survey data — the same source used in nautical charting. Each dive site terrain model is processed individually, with vertical scale calibrated to show real depth relationships accurately. The colour gradient on the underwater terrain maps directly to depth — aqua at the shallows, deepening through blue-green to dark indigo at the bottom. The depth legend scales to the actual range of each specific site. When you're looking at the 3D dive site map for Bare Island and the colour tells you something is at 18m, it's at 18m. "Tap anywhere on the terrain and the depth readout updates in real time. It's the closest thing to having a depth gauge before you're in the water." Depth contour lines are drawn at 5m intervals across the terrain, making it easy to read reef shape and identify drop-offs, walls, and plateaus. The vertical exaggeration slider amplifies terrain height for gently sloping sand sites where 3D shape is otherwise hard to read at normal scale.

How to use Echo³ — first time walkthrough

Open any supported Sydney dive site on the Pelagic map. Supported sites show an Echo³ button floating above the site marker — tap it and the 3D dive site map opens in a new tab, loading the terrain model within a few seconds. The scene opens with a cinematic intro orbiting the site so you can immediately read the overall underwater terrain shape. From there you're in full manual control: Drag to orbit around the terrain from any angle Scroll or pinch to zoom in and out Right-drag to pan across the site Tap anywhere on the terrain to read the depth at that point The compass in the top-left rotates with your view so you always know your heading relative to the actual site. Use it to find north, identify the entry point, and orient the wall direction before you leave the car park. For planned dives, the workflow is straightforward: load the 3D dive site map, orbit to understand the overall terrain shape, switch on Reef Trails, trace your intended route, use the measure tool to check distances, and note POIs along the way. Five minutes and you know the site better than most people who've dived it once.

Reef Trails in 3D — The Steps and The Leap as examples

Reef Trails — the turn-by-turn underwater routes available on the 2D map — are now overlaid directly onto the 3D terrain. The trail tubes sit on the actual seafloor geometry, following reef structure, dropping down walls, tracing along sand channels. You can see exactly how a route moves through space before you dive it. Echo³ 3D dive site map showing Reef Trails at Bare Island, Sydney Reef Trails overlaid on the Echo³ 3D dive site map at Bare Island East. Depth-coded trail tubes follow the actual seafloor geometry. The Steps at Kurnell is a good example of why this matters. On the 2D dive site map the reef trail appears as a coloured line heading east from the entry. In the Echo³ underwater terrain viewer you can see what that actually means — a route that tracks along a rocky ledge before dropping onto a sand flat, then climbing back onto the reef as it hooks south. The weedy seadragon hotspot marked at 8m sits on a specific rocky outcrop that's immediately identifiable on the 3D terrain. You'd spend ten minutes searching for it on your first dive; on Echo³ you find it in thirty seconds. The Leap, immediately south of The Steps, shows the same value from the opposite angle — it's a deeper, more exposed dive, and the 3D terrain makes it immediately clear why. The reef drops away steeply from the entry platform, the wall to the east is sheer, and the sand channel that connects back to the exit runs deeper than the 2D map suggests. Knowing that before you go is the difference between a planned dive and a discovery dive. Trail colours follow the same depth coding as the 2D map — aqua for 0–5m through to deep indigo at 30m+. On the 3D terrain this becomes immediately intuitive: the colour shift and the seafloor shape confirm each other. Surface swim sections are rendered as floating tubes above the water plane, clearly distinguishing above-water transit from underwater diving.

Points of interest, entry and exit

Every pin type from the 2D Reef Trails appears in the 3D dive site map — entry points, exit points, points of interest, and hazard markers — each at its exact position on the underwater terrain. Tapping a POI opens the same description you'd see on the 2D map: the cave system at Bare Island, the cleaning station on the north wall at Shelly Beach, the gutters where the grey nurses rest at Magic Point. The difference is that now you can see exactly where that pin sits in the context of the full site terrain. A POI at 18m on a sheer wall means something different to a POI at 18m on a gradual slope. In Echo³ you can see which one it is before you descend.

The measure tool — real distances, before you dive

Open the ruler and Echo³ enters measure mode. Each click drops a pin and draws a segment showing horizontal distance in metres and compass bearing to the next pin. A running total accumulates as you go. The distances are real — the terrain is built to accurate dimensions, so 80m in the measure tool is 80m in the water. Use it to check the distance from entry to the wall, to confirm your third-of-air turnaround works for the route you're planning, or to measure the swim from Shelly Beach out to the edge of the Cabbage Tree Bay reserve before you decide whether conditions are good enough to push further.

Which Sydney dive sites have a 3D map

Currently 25 sites across the Sydney region have Echo³ terrain models, including the most popular shore dives on the coast — Bare Island East and West, The Steps, The Leap, Shelly Beach (Cabbage Tree Bay), Magic Point, Gordon's Bay, Shelly Beach Manly, and more. The Echo³ button appears on the map only where a 3D dive site map exists. If the button isn't visible on a site, it's not available yet. More dive site 3D maps are being added continuously, prioritised by dive frequency and bathymetric survey data availability. Next priority regions are Jervis Bay and the Mornington Peninsula.

Frequently asked questions about Echo³

What is a 3D dive site map? A 3D dive site map is an interactive terrain model of the seafloor at a specific dive location, built from bathymetric survey data. Unlike a flat 2D dive map, a 3D dive site map lets you orbit the underwater terrain, read depth at any point, and understand the full spatial layout of the reef — walls, drop-offs, sand channels — before you enter the water. Echo³ is Pelagic's 3D dive site map viewer, currently covering 25 Sydney-region sites including The Steps, The Leap, Bare Island, and Shelly Beach. How accurate is the underwater terrain map? Echo³ terrain is built from NSW Government digital elevation and bathymetric survey data — the same source used in nautical charting. Depth values and spatial dimensions are accurate for dive planning purposes. It's a complement to a local briefing, not a replacement — but it's a substantial improvement over planning from a flat satellite image or a text description. Which Sydney dive sites have 3D maps? Currently 25 sites, covering the most popular Sydney shore dives including Bare Island East, Bare Island West, The Steps, The Leap, Shelly Beach (Cabbage Tree Bay), Magic Point, Gordon's Bay, and more. The Echo³ button only appears on the map where a terrain model exists. Does Echo³ work on mobile? Yes. The 3D dive site map viewer is fully touch-responsive — orbit, zoom, and pan all work with standard touch gestures. The cinematic camera modes and measure tool also work on mobile. Is Echo³ included with Pelagic Pro? Yes. Echo³ is a Pro-tier feature. Reef Trails on the 2D dive site map are available to Essential members, but the full 3D underwater terrain viewer, cinematic camera modes, and measure tool require a Pro subscription.