Does it have to completely cover the pump?
I used to race on a boat where the plugs that connected the masthead instruments to the gear below deck kept getting kicked out, which caused quite a few problems. In the end we made up this cover for them, it basically consisted of 2 U-shaped pieces of metal, welded together at 90 degrees to one and other with another circular piece of metal wrapped around the outside of the whole thing. Each 'leg' of the cage then just screwed into the deck. It was dirt cheap, easy to install and stopped the plugs getting kicked out.
It wasn't an off the shelf thing, not sure exactly who made it for us but I imagine that anyone with the right equipment and materials would be able to do something similar.
I don't know if that's easily achievable for you, but it certainly helped us out.