[jedc]

(Former US submariner)

Yes, and no.

Yes- the US has maps with higher-resolution data on water depth around the world than what's commercially available.

No - those maps aren't perfect. Some areas are extraordinarily well-mapped, others are less so.

Submarine crews are trained not to check just the charts that are in use for a particular voyage, but also other charts covering the same area. (The USS San Francisco collision has no evidence of a seamount on the charts in use, but there was "discoloration" on another chart covering the same area.)