winterization

so I have my first jet boat with a 454 I am not real sure how to make sure the block is drained? it has some large plugs underneath the exuast manifold but theirs no way i could get to them without lifting the motor up. when I unhook the hose that the garden hose hooks to a little water comes out is that enough?Or should I just fill it with coolant and not worry about it?

thanks

winterization