Definitions for "Ice Keel" and "Keel" are too restrictive.

[andypbarrett]

There is are two separate entries for "Ice Keel" and "Keel"

Ice Keel
from the point of view of the submariner, a downward-projecting ridge on the underside of the ice canopy; the counterpart of a ridge; ice keels may extend as much as 50 meters (55 yards) below sea level.

Keel
the part of a ridge below the ocean surface; wind, ocean currents, and other forces can push sea ice into piles that rise and form small mountains below the level sea ice surface.

1. These definitions should be the same. I suggest having a single definition assigned to "Keel". "Ice Keel" can "redirect" to "Keel"
2. Keels are not only defined from the submariners point of view.
3. The counterpart of the Keel is a Sail.
4. I don't see the point of mentioning small mountains. It could be misleading and ridge seems a common enough term.

Suggest
"the part of a sea ice pressure ridge that extents below the sea ice cover. Ice keels can extend up to 50 m below sea level."

See also pressure ridge, sail