Spray Rails The Why, What and Where

Spray Rails The Why, What and Where

Posted by Gayle Brantuk on Dec 2nd 2016

One of our Barrelback builders called today asking where the spray rails go and what material to use. On this design the plans call for 5/8" net x 1-1/2" x 20' mahogany or similar for the spray rails. But, you may be asking, "what's a spray rail?" Well, it's a piece of wood attached to the outside of the boat that keeps the water from coming up over the side and soaking your passengers.

Of course, maybe you want to soak your passengers and if so, just disregard this article. I vividly remember riding in the aft cockpit of Butch Barto's Tahoe and the wall of water that soaked me as we were docking. Butch has since added a spray rail.

Butch Barto's Tahoe

Butch Barto's Tahoe

Here's what our book, Boatbuilding with Plywood, says about this appendage:

“Outer chines, spray deflectors or spray rails are often advantageous on plywood craft. These longitudinal members parallel the chine log and are installed after planking. One of their functions is to protect and seal the exposed edge of the plywood bottom planking. Their most important function, however, is to knock down spray… Some spray rails run from the stem to the transom. Actually for spray protection, they need run only from the stem to midships. When run completely to the transom, that portion aft of amidships should follow the contour of the bottom. In the forward section, the rails should have a crisp lower edge to better deflect spray. Such rails should be screw fastened or bolted securely in place. They are usually considered expendable and are applied after planking and fiberglassing if such covering is to be used. They may be bedded in mastic or fiberglass and resin similar to the skeg. However, bedding in resin would make future replacement more difficult.”

I think aesthetics definitely play a part in the issue of spray rails and that of course, is in the eye of the beholder. 

Barrelback

Spray rails on a Barrelback built by Greg Walters in South Africa.

TAHOE 19 by Bill Edmundson

Tahoe built by Bill Edmundson showing his spray rails or "guards". Bill says, "The guards are time eaters. Fairing them to match a constantly changing surface is slow."

So there you have it--the definitive non-answer. As usual, there are as many opinions as there are builders. One of the many joys of building your own boat is laboring over every detail. But truly a labor of love, don't you agree?