Fran Yes you should raise your hood more, Do it the way I suggested above only install the inner 1x6 only say a 1/4" or 3/8" above the new bottom so you well get about 3 1/4" of new height, which well give you a little over 9", which is what My lites at the bottom of the bulb sits above the water. I wouldn,t go any lower than that, cause of splash issues, corrodes your reflecter and gets salt on the bulbs and has to be constantly cleaned. If you wanted more height use a 1x6 to add on the bottom and do the overlay or sistering as is what it is called with a 1x8, either way all you should need well be something to cut the boards to length, a drill to drill some pilot holes with and you can also use as a screw driver, some good polyurathane glue or epoxy, some sand paper to sand the finish off so the glue adheres and to sand before finishing. Make sure to strain and put several coats of say clear polyurathane on so the wood doesn't warp on you from sucking in moisture. Its not very hard to do and won't require a bunch of clamps and precision work and well give you a good strong addition plus a cleat for the canopy to sit on, by the way, as you have probably figured out you well have to remove the old cleat around the inside of the canopy. Good luck.
