The stone wall does not clog the wall, making it visible underwater, and when the block is placed, the water will flow out.

Caves & Cliffs 1.17.1 Release Candidate 1 Datapack Preview
World Type: Default
Seed: 63654350
Coordinates: /execute in minecraft:overworld run tp @s -338.49 -1.00 -63.82 281.75 0.64

biomes: deep ocean