Good point to bring up for this time of year Bill.
I've patrolled the lakes for years and took multiple reports of vehicles being broke into. In those calls, here's what I took from them...
Most of the reports come in the winter/early spring. Reason being is that there are few, if any campers in the area, so the thieves know unless they hear a vehicle or boat coming, they are safe to bust the window, rummage thru your stuff, and leave within minutes.
Most thieves know that we are outdoorsmen, and carry guns in our vehicles. Those of us that do, rarely remove it from our vehicles and into our boats while on the water. Thousands of firearms are stolen from vehicles at ramps every year.
Usually there are fewer people just out for a drive around the ramps at this time of year, so the thieves know they are less likely to be seen or heard.
The preferred method usually is a rock thru the window. Nothing I hate more than a thief.