This design might work at sea, but would fail in “brown water” (near the coast or in rivers), because of submerged obstacles, e.g. water logged timber. One good hit by a water logged tree branch could ruin one of the “propulsion units” and cripple the boat. This happened to one of the Navy’s hydrofoil boats in the 1970s and completely totaled it.
After hurricanes and tropical storms, the coastal waters are full of floating debris mainly from docks and decks......................