The snail is damaging when out of its shell so Samus must face the center of the snail to cause it to hide.
The snail climb consists of Samus jumping away from the snail as it becomes active, then turning around to return to the snail and resposition for the next jump.
Standing on the edge of the snail and turning around underwater does carry the risk of falling off.
Spring Ball can bounce on an active snail (only one bounce when underwater without HiJump).
Snails can be used as single use platforms without it being considered a snail climb.
See also: Tech Page