Ocean Floor Map

Saint Lawrence River depth map

Channel: average depth about 194 m, deepest 392 m (GEBCO_2026 grid).

Tap or scroll to load the interactive map

Sea level todayDrag the slider to lower the sea and see the land that would appear.

Sea level in metres below today’s. A simple bathtub model: it lowers the sea everywhere by the same amount and does not simulate how the water would really drain.

Key

Sea depth

  • Deeper than 6,000 m
  • 4,000 to 6,000 m
  • 2,000 to 4,000 m
  • 1,000 to 2,000 m
  • 200 to 1,000 m
  • Shallower than 200 m (the continental shelf)

Land height

  • Land up to 500 m
  • 500 to 2,000 m
  • Above 2,000 m

Drain the oceans

  • Seabed exposed when the sea is lowered A dashed white line marks today’s coast.

How to read the map. Darker blue is deeper water. Tap anywhere to see how deep the sea is there, or how high the land is, and the nearest named undersea feature. Depths come from the GEBCO_2026 grid, which in most of the deep ocean is predicted from satellite measurements of the sea surface rather than surveyed by ship, and the map’s tiles are coarser than the grid, so narrow trenches read shallower on the map than their true depth. Not for navigation.

Saint Lawrence River at a glance

  • 194 maverage depth
  • 204 mmedian depth
  • 392 mmaximum depth
  • 34,845 km²water area

Saint Lawrence River is a channel. Inside its outline the GEBCO grid has about 34,845 km² of water, with an average depth of about 194 m (the middle value is 204 m) and a maximum of 392 m, found at 49.44° N, 65.11° W.

Open the map at the deepest cell and tap to read the depth.

How deep is each part of the Saint Lawrence River?

The bar splits the Saint Lawrence River's water by depth. Each colour is a depth band, and the shares add up to 100%.

  • 0 to 200 m: 49.1%
  • 200 to 1,000 m: 50.9%
  • 1,000 to 4,000 m: 0%
  • 4,000 to 6,000 m: 0%
  • below 6,000 m: 0%

Named features near the deepest point: Fundy Basin (479 km), Grand Manan Basin (564 km), Murr Basin (567 km), Emerald Basin (618 km).

The Saint Lawrence River if sea level dropped

The slider on the map lowers the sea in steps. This table shows how much of the Saint Lawrence River's water would be land at each step.

Sea level lowered byBecomes landShare of its water
10 m3,158 km²9.1%
20 m4,337 km²12.4%
50 m6,491 km²18.6%
80 m8,254 km²23.7%
120 m11,161 km²32%
200 m17,098 km²49.1%
500 m34,845 km²100%
1,000 m34,845 km²100%
2,000 m34,845 km²100%
3,000 m34,845 km²100%
4,000 m34,845 km²100%
6,000 m34,845 km²100%

A simple bathtub model: it lowers the sea everywhere by the same amount and does not simulate how water would really drain.

Nearby seas

Nearest by the centre of each outline. All oceans and seas

Frequently asked questions

How deep is the Saint Lawrence River?

On average about 194 m in the GEBCO grid (the middle value is 204 m). The deepest cell inside its outline is 392 m, at 49.44° N, 65.11° W.

How big is the Saint Lawrence River?

About 34,845 km² of water inside its Natural Earth outline, counted from the grid cells that are below sea level.

How much of the Saint Lawrence River would be land if sea level dropped?

With the sea 10 m lower, about 3,158 km² (9.1%) of its water would be land. At 6,000 m lower, 100% would be. This is a simple bathtub model that lowers the sea evenly everywhere.

Data: depths from the GEBCO_2026 grid, statistics worked out inside the Natural Earth outline of the channel. See data sources and licences. The GEBCO Grid should NOT be used for navigation or for any other purpose involving safety at sea.

All oceans and seas · Undersea features · Drain the oceans

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