ROLLER TRAILER POINTS
Trailer more expensive to purchase and maintain
Boat weight distributed over many different points
Needs winch to retrieve the boat at the ramp
No need to submerge the axle
No friction points to deal with
Can launch or retrieve at any tide stage
Usually no “drive-on”
BUNK TRAILER POINTS
Trailer less expensive to purchase
Fewer parts to maintain
Use Keel rollers to center the boat and to support a small part of the boat weight
Trailer must be in relatively deep water to launch/retrieve
Running gear, brakes, hubs, springs etc will be submerged
Boat only supported at contact point with the bunk and keel rollers
Lighter weight winch can be used with “drive on”
Bunks can scrape paint due to friction
Some boat manufactures require the use of a bunk trailer
One of the main advantages of the roller trailer is that the running gear, which includes springs, axles, hubs, brakes etc does not have to be submerged. This is a great benefit, especially in salt water, which causes corrosion problems. In many ways, the decision between the two styles comes down to whether you want to drive the boat on the trailer. If yes, then the bunk trailer will be the best bet. If no, go with the roller trailer. Driving on works best if, during retrieval, a member of your crew is available to get the tow vehicle/trailer and back it down the ramp. If you are boating alone or with young kids, it can be a chore to tie the boat up, go get the tow vehicle/trailer and back it down the ramp. Then you have to leave the tow vehicle, get back on the boat and drive it on the trailer etc. You can see that it could also be dangerous leaving the tow vehicle unattended while retrieving the boat.
Trailer Parts Superstore carries a device that could make this operation a little more secure. This device is called the Snapper and is a remote controlled latching mechanism (securely latches boat bow eye to the trailer bow stop) using a handheld remote control.
Trailer Parts Superstore also carries many replacement parts for both styles of trailers including replacement rollers and bunks, winches, bow stops and more.