If you use the truck bedliner like Indy shows, be careful especially if you have a Yamaha 4-stroke with stock skis.
I had an Apex and had ski guides that were very similar in design-deep grooves, and due to the keel design on the Yamaha ski, the skis would actually get wedged into the grooves when loading the sled on the trailer, would get about half way up and need to drag it back down-couldn't use reverse as it would just spin.
Replaced those ski guides with EZ Off trailer slides and no problems since.