This is a surprisingly dangerous situation as the below waterline outlet makes a siphon quite possible even with a loop of hose. This can and does sink
boats.
While a check valve should
work, they can easily stick open without showing any sign of trouble making the siphon again possible.
Loop the hose up as you plan but put a vented loop at the top of the hose (which should be higher than the water level when the
boat is at maximum heel. These vents are readily available.
Carl