Synonyms for Submerging:

n.

submerging (noun)
submersion, immersion, submergence.

v.

flooding (verb)
sluicing, sloshing, Deluging, rinsing, Imbuing, Saturating, Showering, soaking, drenching, Swamping.
immersing (verb)
sinking, Drowning, dousing, Plunging, Wallowing, Engulfing, Dipping, flooding, Immersing, bathing, dunking, Inundating.
lowering (verb)
depressing, dropping, lowering, shortening, deepening.

Other synonyms:

Other relevant words:
submersion, immersion, submergence.