Possible Modification Project?

[SLOWDUK]

I bought my ’88 V20 Dual Console just before Thanksgiving and have only had it on the water 4 times since, just running around Pensacola Bay and some of the bayous feeding it. Our family plans on using the boat for bay fishing primarily with the occasional fishing trip into the gulf. Waterskiing was a favorite of mine growing up and I would like resume that as well as teach my grand children how to ski. When I described the boat on the forum, several of you noted the large heavy engine (a 630lb 2005 Yamaha 225 four stroke) as too heavy which could reduce the transom freeboard and cause water to back flow into the cockpit through the scupper drains. My limited experience so far has indicated that yes, with a couple of adults standing just in front of the engine, water starts percolating up through the scupper drains and the engine well stars filling with water. A significant concern of mine is the lower transom height in the event of waves approaching from the stern. Never one to accept unnecessary risk and always looking for another do-it-yourself project, I’ve come up with a plan to alleviate the problem. I’m asking the forum for advice and consideration. Maybe one of you has already attempted such a fix.
First, are my concerns warranted? Does the extra weight astern constitute a significant risk?
If so, consider the following modification.
I plan to design, build and attach to the transom buoyant hull extensions left and right of the engine. These extensions would be shaped so as not to interfere with the engine’s range of motion nor touch the water with the boat on plane. Measurements indicate that there is a space 30 inches wide left and right of the motor to work with. Preliminary calculations indicate that if they extend aft 24” from the transom, 4 to 5 cubic feet of volume can be displaced below the waterline with the boat at rest (approximately 250-300lbs of buoyancy). And maybe more importantly, additional volume above the water line will add additional buoyancy in the event waves approach from astern. The design will include ladders and handrails so that the extensions double as boarding platforms.
I am considering a wooden and foam design covered in fiberglass or an all aluminum design that my son, who is a skilled welder, can assist in fabrication.
There will be those of you that recommend trading in the motor for a lighter one, but I have initially ruled out that option as the motor (a 2005 with 130 hours on the clock) has considerable life remaining and I like the additional horsepower with the quietness of a four stroke.
I’m pretty much thinking out loud at this point. I have other projects higher on my priority list and I’m not in a rush to execute this plan tomorrow. But I am asking for your experience and insight on this subject.
Thanks in advance, Slowduk