Immersion shielding

From Memory Alpha, the free Star Trek reference

Immersion shielding is a deflector shield configuration designed for a fluid environment, such as air or water.

It was first used by Tom Paris, Seven of Nine, Harry Kim, and B'Elanna Torres during the first flight of the Delta Flyer in 2375, into the atmosphere of a gas giant to retrieve a multispatial probe. (VOY: "Extreme Risk")

Later that year, immersion shielding allowed the Delta Flyer to explore the Monean Waters. In conjunction with structural integrity field, the Delta Flyer could survive pressures at depths of 600 kilometers. (VOY: "Thirty Days")