In Skjold class patrol boats this is achieved by augmenting the buoyancy by incorporating a fan-blown skirted compartment between the two rigid catamaran-type hulls.
The larger inflatables with semi-rigid or rigid hulls are truly ocean-going craft.
"It's what makes a warship's hull so rigid," confirmed the emperor.
The craft, a rigid hull inflatable boat, weighs two tons, and is seven meters (23 ft) in length.
Most small craft intended as lifeboats with rigid (rather than inflatable) hulls designed since about the middle of the twentieth century are self-righting.
The advent of powered balloons, called dirigible balloons, and later of rigid hulls allowing a great increase in size, began to change the way these words were used.
With its bulk and rigid hull, the ship accomplished what all of the captains' weapons couldn't achieve.
These machines (and the HM2s) were catamarans with twin rigid hulls and flexible skirts fore and aft.
The boat differ from other Telstars in having rigid hull joins, with no ability to fold it for trailering.
Buoyancy is augmented underway by a fan-blown skirted compartment between the two rigid catamaran-type hulls.