If you are really concerned about the solenoid in this scenario then you can interpose a timing relay between your MOB
device and your existing solenoid. A "single shot" or an "interval" timing relay would accomplish your objectives, taking a signal that is continually on and turning it into a signal that is on for a fixed time (10 seconds? 30 seconds?). I'd use a single
shot myself as it will ignore multiple pulses from your MOB
device should it deactivate and then reactivate, but either would work.
There are tons of options for 12V timing relays, eBay and Amazon have lots. McMaster-Carr
has lots of options like this one. They won't be the cheapest, but may be the easiest. They (and others) also sell surface mount solid state models that may be better in marine environment
. Personally I'd dig around a bit more and find a "hermetically sealed" version as that helps eliminate corrosion