Re: To Brake or not to brake?
If your axles are in good shape they have brake plates on them.
Just replace the brakes, no need to replace axles to. If your drums are ok, then just replace the brakes and backing plate and wheel cylinders.
Or if you axles will accept it conver to kokiak disk brakes and install a new surge unit.
Brakes are not cheap. I am converting my tandem axle trailer 4200lbs on the trailer axles (had 2,000lb axles with no brakes), to a pair of 3500lb axles with kodiak disc brakes on one axle and oil lube hubs, new springs and such.
With this I have to buy tires and wheels. Cost without the tires and wheels is going to run about $1500, add the tires/wheels and I am into it for about $2,000. A $100 or so is rust bullet to coat the axles, springs, and such since I use it in salt water.
I agree with the others, to be legal I am sure you need brakes. However there are many boats without brakes like yours. Just look around at the boat ramps. I towed my 4500lb boat for 4 years with no brakes and I was ok. 4 wheel disc brake 3/4 tone pickup. But since I now added a camper to my pickup I am adding brakes since total weight of pickup/camper/boat is 15,800lbs.
I am ordering my brakes from Southwest Wheel in texas, they had the best price even with shipping.