I don't lash a hardshell dinghy to the foredeck, ours is inflatable. But in line with where Cam was going, I use preformed, medium density foam "stringers" for cushioning my scuba tanks horizontally to the floor of a cabin locker. Shock cord with end clips are then used to lash the tanks to pad eyes.
That could be a KISS approach to avoid through-bolting your deck, using existing deck hardware as tie-down anchors.
True Blue . . .
sold the Nauticat