The section under the splash well is solid. Im stripping it, soaking it with penetrating epoxy, and bilge paint.
Having some Weights ready for the install is good advise. I am using this Honeycomb composite board from Express Composites.
The stuff is fairly flexible and easy to cut until you glass it on both sides. Then its tough as nails. and the whole sheet weighs maybe 2 pounds. Tomas at Express set me up with this and the 1.5 OZ glass mat / resin to blanket it once its cut to size.
I saw a thread where someone used those polypropylene foam swim noddles. Since their pre formed with a hole down the center the drainage is built in. I'm pretty sure I'm just going to stuff the space where the foam logs were, with noodles.
Oh Yea, and its almost 1/4 moon and I will consider doing it between 2:30 am and 6:oo am so it does not sink.