CONTINUOUSWAVE

Modifying the stern [of a 22-foot Outrage-style hull with notched transom and the narrow sink splashwell] to prevent flooding over the transom onto the deck is a tremendous upgrade to the original design.

What material can be used to make a stern shield [or transom boards as they are more often called]?

Where should a stern shield [or transom board] be placed?

[Moderator's note: separated from another discussion on an entirely different topic.]

The idea of adding splash boards to reduce the amount of water coming over a transom is nothing new. The topic is discussed in prior threads:

Outrage 22 Transom and Splashwell Modification
http://continuouswave.com/ubb/Forum3/HTML/021302.html

Raising Splashwell Dam
http://continuouswave.com/ubb/Forum3/HTML/016584.html

22-REVENGE CUDDY: Water Over Transom
http://continuouswave.com/ubb/Forum1/HTML/010698.html

Because a splashwell board will be exposed to continual contact with water, the material for the board should be suitable for immersion in water. Wood coated with epoxy is a possible choice. Plastic sheet material is another choice.

The plastic sheet material sold under the brand name KING StarBoard is a plastic sheet material that could be used, but I don't think there is anything unique about it other than its premium price.

The most important element in fabricating and installing transom splash boards will be the method of attaching them when needed. There could be considerable force exerted on a transom splash board if a large wave were to come over the notched transom. The mounting of the transom splash board would need to be sufficiently strong to resist the bending moment created by the wave force. Also, unless the transom splash boards were to be a permanent modification, the boards will need to be removable when not needed. That requirement can also complicate the mounting method.

Regarding the material, it might be better to use a material that was buoyant in water in case the boards were dislodged from their mount and sweep into the sea. You could recover them if they float.

Vance's Revenge wrote:Modifying the stern [of a 22-foot Outrage-style hull with notched transom and the narrow sink splashwell] to prevent flooding over the transom onto the deck is a tremendous upgrade to the original design.

Regarding whether splash boards ought to be added to the wide notched transom of an Outrage-22 -style hull, any board that prevents water from entering the boat by the transom will also prevent water from leaving the boat via the transom. The notion that adding splash boards, especially splash boards that are permanently installed, is going to be "a tremendous upgrade to the original design" is not necessarily guaranteed.

Boats are made with large open transoms specifically to permit rapid draining of water into the sea from water in the cockpit. Building obstructions to water draining out and over the transom could prove to be very detrimental if the cockpit becomes flooded with water.

Perhaps by adding some type of a spring loaded hinge and designing the splash shield so that it only opens to let water out you could get the benefit of a splash shield and still allow water to exit if needed.

At some time ago I looked into [adding transom splash boards to the notched transom of an pre-c.1990 OUTRAGE 22].

An [Outrage] 22 Splash Well Bulkhead Kit # 15-0744-00 that did indeed have a one way hinged door to allow high water drainage out the stern [was offered],

[The Splash Well Bulkhead Kit] may be something of a starting point in fabricating your own design.

Splash boards should have two rectangular openings with hinged flap that only swings toward the stern.

Rough dimensions for an appropriate opening would be 4" high x 11" wide.