Boat Trailer Brakes: Surge vs. Electric-over-Hydraulic

There are plenty of advantages to owning a trailerable boat as opposed to one that you keep in a slip or on a mooring. If you’re shopping for such a boat, bear in mind that with a vessel of a certain size and weight you’ll need a brake system on your trailer. And in the world of trailer brakes there are a couple of options to weigh.

Depending on the technology, I tend to vacillate between being an early adopter and an abject Luddite. I bought a vehicle with fuel injection as soon as I could afford one—and would never go back to carburetors—but I hung back and waited a while before buying a smart phone.

When it comes to boat trailers, I’m sort of trapped between the two ends of the adoption spectrum. I’ve heard that electric-over-hydraulic brakes are making inroads into the boat trailer market.

Electric-over-hydraulic systems are great for larger boat trailers because they offer the benefit of adjustment and smoother operation — but they are more costly than conventional surge-brake systems.

On one hand, I ask, “What was wrong with surge-activated disc brakes?” They’re largely idiot proof; they have a terrific service history. Their reliability is exceeded only by their simplicity, and they are cheaper to manufacture. On the other, I kind of like the idea of electric-over-hydraulic brakes. The latest hardware includes controllers that are no more difficult to install than plugging them into your tow vehicle’s cigarette lighter… er… 12-volt outlet.

A typical surge-brake actuator. Photo courtesy of Atwood.

The controllers allow for fine-tuning, which is something I would have appreciated when I was towing a 38 Wellcraft Scarab with surge brakes. Yes, the surge brakes stopped the trailer well enough, but when you lifted off the brake pedal to accelerate, the release could almost be described as violent. The return spring in the master cylinder slammed the piston back out, and it really jarred the truck and its passengers.

So maybe that’s the difference:  Surge brakes are still good for applications up to and including, say, 7,000- or 8,000-pound boat trailers. Anything from there up could benefit from the smoothness and adjustability of electric-over-hydraulic.

I think we might begin to see more of electric-over-hydraulic systems used on boat trailers, probably on high-end stuff at first. However, I think for runabouts and other boats that weigh 7,000 pounds or less, the simplicity of the surge-brake system is hard to beat in function or price.

Brett Becker

For much more on marine trailers, trailer brakes, and safe trailering, see the following: