First of all, I am certain that the beach wheels offered by the sponsor are far superior in performance and ease of use than a Qtip style roller for the usual trailer to beach and beach to trailer use.

For coastal cruising, I use qtip style and they are a great thing to have along when you can't find a perfectly shaped log.

To answer the question about how well they stay aligned: The boat is rolling on a pair of inflated fenders. The fenders work well in maintaining floatation in wet sand, dry sand, and silt. The pipe in the middle is simply there to maintain the proper width spacing (via compression) and to give you a way to grab both rollers at once without having to pick up each of the two rollers. The bungie maintains the proper width via tension.

With good bungie tension, they work quite well and don't go askew very badly.

By the way, the Polyethylene 3" pipe runs about $3 / 10 feet.

GARY