When you're designing these things, just when you think you're safe to go back into the water, another shark pops its fin up.
Specifically the two quads will have to be joined with a spacer, a little like the filling in a sandwich, to ensure that the propellers and motors are basically contained within the vertical depth of the airframe... in other words so that they do not stand proud of the deck.
(You can see that better in the profile view of the 1:10 scale model below.)
Exactly how thick that spacer needs to be is as yet an unknown quantity, as the specs for the motor show only its own depth ~ six centimetres ~ and not that combined with the propeller.
This I shall do myself with a ruler, as computer-aided design is well above my pay-grade.