Ocean Floor Map

Massachusetts Bay depth map

Bay: average depth about 37 m, deepest 99 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.

Massachusetts Bay at a glance

  • 37 maverage depth
  • 32 mmedian depth
  • 99 mmaximum depth
  • 3,397 km²water area

Massachusetts Bay is a bay. Inside its outline the GEBCO grid has about 3,397 km² of water, with an average depth of about 37 m (the middle value is 32 m) and a maximum of 99 m, found at 42.46° N, 70.59° W.

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

How deep is each part of the Massachusetts Bay?

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

  • 0 to 200 m: 100%
  • 200 to 1,000 m: 0%
  • 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: Sharrer Ridge (127 km), Cashes Ledge (136 km), Franklin Swell (148 km), Howell Basin (156 km).

The Massachusetts Bay if sea level dropped

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

Sea level lowered byBecomes landShare of its water
10 m408 km²12%
20 m921 km²27.1%
50 m2,381 km²70.1%
80 m3,194 km²94%
120 m3,397 km²100%
200 m3,397 km²100%
500 m3,397 km²100%
1,000 m3,397 km²100%
2,000 m3,397 km²100%
3,000 m3,397 km²100%
4,000 m3,397 km²100%
6,000 m3,397 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 Massachusetts Bay?

On average about 37 m in the GEBCO grid (the middle value is 32 m). The deepest cell inside its outline is 99 m, at 42.46° N, 70.59° W.

How big is the Massachusetts Bay?

About 3,397 km² of water inside its Natural Earth outline, counted from the grid cells that are below sea level.

How much of the Massachusetts Bay would be land if sea level dropped?

With the sea 10 m lower, about 408 km² (12%) 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 bay. See data sources and licences. The GEBCO Grid should NOT be used for navigation or for any other purpose involving safety at sea.

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