Preparing a trailer boat for on-road safety while towing to and from a launch ramp calls for securing the transom eyes to the trailer with a pair of properly rated transom tie-down straps, in addition to securing the bow eye with the winch strap and safety chain.
A pair of transom web straps generally connects the transom eyes to corresponding tie-down points on the back of the trailer, tightening with a buckle or a ratchet. Traditionally, you store the straps in your tow vehicle after you launch.
However, one type of transom tie-down strap is engineered to remain attached to the trailer. These are known as retractable transom tie-down straps, and they were first introduced in the 1990s by Boat Buckle. The design concept has since been copied by a number of other companies, including BetterBoat, CargoLoc, Fulton, RhinoUSA, Strappino and others.
While retractable transom tie-down straps are fairly easy to install, there are important factors to keep in mind when choosing straps and mounting methods to maximize longevity of the system and help ensure that the boat is secured as well as possible to the trailer while towing to keep the hull from sliding about or bouncing on the bunks or rollers.
For this installation of retractable transom straps, we focus on a 21.5-foot center-console trailer boat that weighs approximately 4,000 pounds without the trailer and is used primarily in salt water. Here’s how the installation went.
Skill Level: 1 of 5
Finish Time: Approx. 2 hours
Tools and Supplies
- BetterBoat retractable 43-inch stainless-steel ratchet tie-down straps ($73.99 per pair with adapter brackets and hardware; amazon.com)
- Power drill and drill-bit set
- Socket-wrench set
- Box/open-end wrench set
- Tape measure
- Cold-galvanizing spray paint ($21.90 per CRC Zinc-It 13-ounce aerosol can; grainger.com)
Select Straps
Retractable transom tie-down strap systems come in a variety of ratings for working loads and breaking strength. Select the highest rating possible for your rig. Better to have straps that are too strong than too weak. Ensure that the straps offer sufficient length to reach the transom eyes from the mounting point. If you boat in salt water, consider stainless-steel models with construction that resists corrosion. In our case, we decided on a pair of BetterBoat stainless-steel models with 43-by-2-inch web straps with a working load limit of 600 pounds and an assembly breaking strength of 1,800 pounds each.
Tip: Stainless-steel models have lower strength ratings than comparable models featuring carbon-steel construction, but the stainless version will cost more. If you boat in fresh water only, you can choose from the carbon-steel models.
Mounting Method
The compact ratchet system will mount in two ways. The standard method calls for fastening a 10 mm diameter bolt through a hole in the rear crossmember of the trailer using a matching washer and nut. The second employs an adapter bracket that bolts to the trailer tie-down that is perpendicular on the rear crossmember. Thus, as with the standard mounting method, the strap deploys flat/parallel to the transom surface, eliminating any twist. Using the adapter bracket also eliminates the need to drill a hole in the trailer, which can break the painted or galvanized finish of a steel trailer and lead to corrosion.
Determine Location
The mounting location for the ratchet on the rear crossmember should align as vertically as possible with the transom tie-down eyes on the boat. Avoid angling the strap more than 30 degrees in any direction from up and down. Also avoid locations that draw the strap across any objects such as the aft corner of the hull, a trim tab or a transom-mounted transducer. On boats with integral outboard brackets or extended aft platforms, deploying the strap across the bottom of the transom might prove unavoidable. If this is necessary, consider placing a towel under the strap before tightening it to forestall wear on the boat finish.
Tip: In deciding a mounting location, be sure there’s enough swing room to work the ratch handle back and forth before you finalize your decision. There might be, for instance, a trailer taillight or trim tab that interferes with the handle or becomes a finger pinch point when tensioning the ratchet.
Mount the Ratchets
If you choose the standard installation method, drill mounting holes in the desired locations, then give the raw metal a couple of coats of rust-fighting cold-galvanizing spray paint. Next, bolt the ratchets securely to the rear crossmember using the supplied hardware. If using an adapter bracket, decide on the best angle for the adapter depending on if the tie-down is in a vertical or horizontal orientation. Use the angle that orients the back of the ratchet mechanism parallel to the transom, allowing the strap to deploy parallel to the transom as well. Bolt the ratchets securely to the adapters using the supplied hardware.
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Deploy and Retract
To deploy and attach the BetterBoat straps, press the button in the middle of the ratchet handle to release the tension, then pull out the strap and attach the vinyl-coated strap hook to the transom eye. Press the button on the ratchet handle and move the handle up, then release the button and work the handle back and forth to tighten the strap. To remove the strap from the boat, press the button in the handle to release the tension on the strap, then remove the hook from the transom tie-down eye, allowing the spring-loaded ratchet to automatically retract the strap into the mechanism like a venetian blind.
Tip: After the first trip with the new retractable tie-down straps, recheck the tightness of the mounting hardware and retighten if necessary.
