JRG,
Thanks for the update. I don't kow how far the anchors go into the hull. They seem to be through just the top of the hull. They swivel as if they were toggle bolts not tightened. I can't see a way to remove them. I don't know what a cutaway look of the hulls are. I just assumed the top of the hulls sat like a cap on the lower portion therfore any hole would allow water into the pontoons.
PS I ordered the catalog, Thanks.