As PADRE mentions, there are two schools of thought about how to wire a bilge pump with regard to unattended or automatic operation.
If you want to bilge pump to be able to operate at any time, then you have to wire the pump directly (through a fuse) to the boat battery, and avoid the main power switch.
If you want to be certain that the bilge pump will NEVER run when the battery switch in in OFF, then wire the pump as part of the loads that are switched by the main battery switch; that is what you seem to have now.
I assume that the boat on the lift has been rigged so the stern is lower than the bow. This is the preferred arrangement for a boat on a lift. With the stern lower, any rain water that comes into the cockpit or other open areas of the boat will run aft and collect in the cockpit sump. If the sump pump is not able to lift that water overboard, then water will rise in the stern of the boat at a rather rapid rate because the collecting area is probably quite large.
Regarding the risk of the aft cockpit of your boat collecting rain water, that worry can be eliminated by unplugging the sump drains when the boat is on the boat lift and raised out of the water. Of course, then you have the bother of having to put back in place the drain plugs before you use the boat.
Phil T wrote:If you rely on the pump and your battery fails, there may be a larger problem.
As Phil alludes, for a boat with only one battery, coming to the boat for a day of recreation and finding the boat battery has been drained by a bilge pump that ran too much and too long will be quite a disappointment. Generally any lead-acid battery whose state of charge is drained to the minimum will suffer a shorter service life. In my own experience and behavior, any lead-acid battery that is a few years old and has been subjected to a very deep discharge has become a liability. I don't trust batteries like that in any sort of critical use; and I consider being able to start an engine to be a critical use.
One perspective on this question can be found by looking at how the boat came as wired from the factory. The boat is a Boston Whaler boat made just two years ago, so it ought to represent the best thinking from Boston Whaler.