Thats why there are electric over hyd systems

Electric over hydraulic is the way to go. Solves all the problems. System is run off the standard electric cab controller, rund an electric/hydraulic pump on the trailer that actuates the brakes.

You're not stuck with them and I don't think electric brakes hate getting dunked any worse than the hydraulics do. I've swapped every set of surge I had over the last 15 years for electric and never had a problem with them. I don't even disconnect them when I back into the lake-which I have to say is really nice to have the ability to have brakes that work backing in on a steep ramp(make sure you have sealed lights and dielectric grease on your connections). I always had issues with the surge brakes and talked to a guy about 15 years ago that was using mobile home axles (electric brakes)under a trailer with a huge Sea Ray on it. He said he towed his boat all the time from Erie to Cumberland and never had any issues with the electric brakes getting wet or failing because of repeated dunkings. I switched mine to electric and never looked back. The increased control is excellent. I've heard that the new elec over hyd systems are really good, especially if you go with the discs, but have not tried them. In any case, dump the surge brakes, you'll be glad you did. If you're going to spend the money completely rebuilding them, you can put in electric for the same money or cheaper anyway. All the electric brake stuff will go on your current axles, toss the surge tongue and buy a solid one, wire it all up and you're done. The only maintenance you'll have is to check the drums/magnets and your shoes at the beginning of each season when you re-pack your bearings, which you would have to do anyway. If your drums are crusted over where the magnets ride, take an angle sander with a scotch-brite pad and remove the oxidation so it doesn't eat your magnets. That's all there is to it.

E/H kits. Kodiak is good stuff. Cheap insurance!

http://www.etrailerpart.com/ultimateproseries.htm

Master cylinder is probably rusted/froze up. I know when I was going through my trailer brakes/bearings this fall I found leaky grease seals/grease filled drums and worn to the lining shoes. Replaced the bearings/seals and shoes and found rusted solid wheel cylinders, changed those and tried to bleed I found dry lines and a rusted/frozen master cylinder. Luckily I keep my boat racked so the trailer doesn't get much use but from what I can tell the trailer brakes hadn't worked for awhile (just bought the boat last year). So I bought a new master cylinder for the time being, but I'll probably do a disc conversion next year. Eagle trailer/Dico brakes btw.

You know, I guess I'd have to admit I haven't personally tried using electric brakes on my boat trailer... but I'd sure love to, they work SO much better.
You've got me seriously considering a swap.

Anyone else have electric boat trailer brakes and no issues with getting dunked in the lake? How about saltwater? I generally avoid putting my boat in salt but I might get a wild hair someday.

I went from Hyd. to electric on my last boat, getting ready to do it on current boat, its pretty much a no brainer.

If used only in freash water, electric brakes are doable. But the magnets in the wheels rustup very fast, maybe if flushed each time they may last a while longer. I would opt for the ele over hyd with disc. The best of all worlds and just flush after that salt water dunkin..................