We all while their to save them. And obviously, those of us who have occasion to launch boats live in fear of becoming one of the poor saps in the videos. But why do cars slide in there, anyway? Can you prevent it?

Turns out, there are a lot of reasons why trucks find themselves in the water. The video above gets into a few of them. Sometimes boat launches get covered in slippery algae, sometimes drivers forget to put the tow car in park. Sometimes the momentum of a heavy boat tugs a tow vehicle with enough force to overcome traction.

One cause that isn’t mentioned in this video is leaving a boat strapped down to the trailer when it hits the water. The way I’ve heard it explained is that people use a strap to hold the boat, especially smaller, lighter boats to the trailer and forget to remove it when they start putting the boat in the water. When the boat starts floating, it pulls up on the strap and on the trailer, which takes weight off the truck’s rear wheels causing them to lose traction or even float. A rear wheel drive tow vehicle or one that doesn’t have the front drive wheels engaged is then free to roll down the ramp and into the water.

To prevent this, experienced boat ramp users recommend putting taking your time and moving deliberately, even if there’s a long line of people waiting to drop their boats after you. Before you let your foot off the brake for any reason, make sure that you’re in the gear that you want to be in and if you’re leaving the drivers seat, make sure the parking brake is engaged. Check out the surface of the ramp to make sure it’s not too slick. Engage four wheel drive if you have it, and make sure the boat is free to float once it hits the water. I always hold the brake with my left foot and give the car a little gas so I don’t roll back, or with a manual use the handbrake like I’m backing up on a steep hill. You can also use a wheel chock for an extra layer of protection.