Intruder alarm for boat on the hard

[masonc]

I'd like a loud alarm if someone gets on the boat, or opens the engine hatch. It would need five wireless contacts. I don't need cellular connectivity, the alarm siren will alert security.

[TheGoldenFleece]

If all you’re looking for is something to make noise, I’d look at something like this:

GE Personal Security Window/Door Alarm, 2-Pack, DIY Home Protection, Burglar Alert, Wireless Alarm, Off/Chime/Alarm, Easy Installation, Ideal for Home, Garage, Apartment, Dorm, RV and Office, 45115 https://www.amazon.com/dp/B00178HMCI..._UwsvBbJKNVM03

A more full-fledged alarm system is pointless without having any central monitoring, IMO.