The least aerodynamic loss way to get MC-27Ls to land on water is by skis just like the Stroukoff YC-123E Pantobase system did. Loss of just 10 mph of airspeed is the penalty: 290 mph instead of 300 mph. Upon landing in the water, the MC-27L with skis slows to a halt and then sinks
into water so its fuselage would have to be made watertight and wingtip
floats added. Rear ramp as its currently hinged at cargo floor could not
open to splash in M113A4 Amphigavins, reducing insertions to just
personnel and cargo through side jump doors; small boat teams with
deflated Zodiac boats (limp ducks) could be inserted/extracted at most.
The C-27Lís engines might have to be inverted to keep water spray out.