Yes, I'm going to add spray rails. It's become a question of exactly where?
The 6 pics below from the rat rod test run at WOT are influencing my thinking, particularly the second and third, bearing in mind these pics were taken in a sheltered arm of the river on a windy day, where the ride was dry. At WOT going into a chop around the corner, the going got rather wet.
My current thinking is to run the spray rails from about one foot aft of the bow and parallel to the gunwales, until they run parallel to and just above the antifoul line until just shy of mid ships, similar to a boat I greatly admire, the Pulsifer Hampton launch (last pic).
Feedback on this approach sought and appreciated.