Fast-Rails

[Bob_Lee]

I was curious if anyone had tried the Fast Rails as well as the Smart Rails.
The owners' comments posted on their website seem like there is quite a substantial fuel savings to be had. Can such an improvement be found with 8 feet of pvc stuck on the chines?

[jcollins]

Hi Bob_Lee,
Check out this thread...

http://albinowners.net/aog/viewtopic.ph ... mart+rails

[Bob_Lee]

It was a combination of skeptical comments followed by users with positive comments on the spray reducing qualities of the smart rails. While the PVC and adhesive attachment was met with skepticism, airplanes have had good results with composites and adhesives, so I did not have a bias there.
The fast rails, however were a curious thing. A few feet of deflection rail in a critical location on the aft chines with such claims of success. Now don't brand me as a skeptic... I just like to hear from happy users who precede me. Any pilots in the group may know that VGs (vortex generators) are just little plastic tabs about an inch long that are stuck to the leading edge of wings and can greatly reduce the stall speed and improve low speed handling, so technology can produce some interesting and desirable results.
If the claims of Fast Rails are real results, the devices would pay off in fuel savings quickly.

[Mariner]

The skepticism of any such device is largely rooted in the belief that, if they provided only benefits, they most likely would have been incorporated into the original design.

The obvious truth, however, is that not every naval architect is perfect, and not every hull is perfectly suited for every situation and use. A perfect example is the ubiquotous 32' to 47' Bayliners. Their hull suffered from a design flaw in that it didn't have enough displacement aft after they changed the powerplants to the larger, heavier versions that the post oil-crisis consumer demanded. This caused them to have difficulty planing and reduced their efficiency. A cottage industry sprouted up and began producing fiberglass add-ons that essentially converted the hull from a semi-displacement, to a hard-chine planing hull.

Ideally, when Bayliner increased the size of the powerplants, as the boat's intended use changed over the years, they should have also considered changing the hull shape to match it. Of course, they didn't, which isn't a surprise, since, they are Bayliner, after all.

But, of course, the add-ons weren't all good. They reduced efficiency at displacement speeds and probably negatively impacted performance in beam and quartering seas (at low speed).

So, it all depends on your use, and what you expect your boat to do. Modifying the hull, whether it be changing the shape, or adding "rails", will always have negative consequences. You just have to weigh the cost/benefit given your use habits.

I would imagine that rails along the chine towards the stern would slightly improve your TTP (Time To Plane). However, they may come at the cost of more rocking in beam seas, or even a loss of stability in high speed turns. Extensive testing would be needed to determine the full impacts.