What does "standard bell" mean?

In Mission Impossible - Dead Reckoning Part One (2023), the Captain’s submarine is at a certain depth below the surface, with a safe distance to the ice canopy above. The Officer of the Deck, responsible for the submarine’s operations and navigation, reports that they are a certain distance from deep water and are approaching a location known as the Aleutian Precipice:

Captain: Ranging maneuver. Helm, left 15 degrees rudder. Steady course 100°. Come up easy on a standard bell.

What does "standard bell" mean?

'Bell' is naval terminology for requesting speed changes. So 'standard bell' is requesting standard speed, as opposed to 'one third', etc.

It relates to the signalling that used to be in place on ships between the bridge and the engine room using an Engine Order Telegraph (EOT).

It's kind of hard to find good references for this, but it is contained in this Wiktionary Glossary of US Navy Slang.

Bells:

[A] Method of requesting speed changes from the Engine Room using the Engine Order Telegraph (EOT), normally from the Bridge. (example: 1/3, 2/3, Full, Standard, Flank, B1/3, B2/3, BI, BEM)