IR sensors will detect the heat generated by someone in your boat. It's
ultrasound sensors that would be trigered by the motion of something moving
in your boat. But what if the boat's interior is heated to higher than the
body's temperature on a sunny day? I dunno enough about this to risk a
categoric answer. But I GUESS it would generate a false alarm.

Jean Dufour
Montreal, Qc

John Smith wrote:

Looking for some advice on the most appropriate sensors for a moored
cruiser. I have switches on the door, the hatch and some windows, I have
two infra red motion detectors and a pressure mat.

Are the IR detectors any good on a boat that sways a lot in the wind etc?
Any other options?

Thanks in advance