She has two parts, a hull and a cabin. The hull operates under the surface of the sea in calm, undisturbed conditions. The cabin is perched above the waves. The two parts are connected by a lifting mechanism. Marine vessels generally are stable because of their shape, long, thin and deep. By contrast ‘Sea Flyer’s’ hull is wide and shallow. This shape provides impressive stability, especially when operating below the surface of the sea. The hull provides the buoyancy up-thrust needed for the whole vessel and will always float. To ensure that she will always float all unused voids, spaces and volumes are filled with expanded polystyrene; this provides permanent indestructible buoyancy.

Capsizing usually results from rolling and then rolling too far. On ‘Sea Flyer’ the various control systems keep her level, she is not allowed to roll. On larger vessels, those carrying vehicles, large numbers of passengers or unstable freight a different arrangement is used. The complete hull volume, apart from the ‘engine room’, contains many air bags. Each air bag has an on/off valve and the bag is connected to an air compressor; all the bags contain air to provide buoyancy and are controlled by a level sensing control system. During loading air can be added too or expelled from individual bags to keep the vessel level, whilst maintaining the overall buoyancy.

The cabin also has potential buoyancy due to its volume in its own right; but perched above the waves it is surplus to requirements. However, in a crisis if all power fails the hull will float to the surface, the cabin will gently settle down onto the hull and the cabin then becomes a very comfortable lifeboat.

Comfort is ensured by the ‘flight control system in the hull keeping it dynamically level and stable at all times and furthermore by a similar system in the cabin, keeping that level and stable at all times. The usual side to side motion (rolling) is not allowed to happen. Similarly the heaving up and down motion (pitching) is eliminated. Since all of the noise producing machinery is in the hull the cabin is very quiet. The comfort level achieved on ‘Sea Flyer’ is undreamed of.

Conventional vessels are at the mercy of wind, wave and swell. Their ability to survive in varying weather conditions depends in the most part on their size.

The hull of ‘Sea Flyer’, being below the surface of the sea, will survive whatever the conditions are. Similarly the cabin being above the waves is not subject to impact shocks from the waves. The distance between hull and cabin determines the sea state that can be accommodated. The design of the lifting mechanism, in the form of a series of pyramids, is of itself a very strong construction. So it almost comes down to specify the sea state and design accordingly.

The propulsion units being outside the hull can be removed and replaced in situ without the need for dry-docking; similarly with damaged hydroplanes. A complete hull or a complete cabin can be replaced whenever necessary. Individual damaged lifting mechanism elements can also be exchanged new for old. The individual elements are not joined at the cross over points. With the amount of electronic control in use continuous monitoring and diagnostic routines ensure that the vessel can be maintained easily and spares kept to a minimum level. Since she is all-electric fuel storage is not necessary with all the savings that entails. Electric motors are more reliable and need far less maintenance than other forms of marine engine.

Another feature of ‘Sea Flyer’ is her ability to make use of the ‘Continuous Air Film Effect’ (CAFE), whereby approximately 80% of her wetted area is not in direct contact with water; almost eliminating the drag due to her passage through the water. This reduction in drag benefits the operator by lower energy costs.

A further feature of ‘Sea Flyer’ is its ability to carry a module under and connected to the cabin. In use the module is positioned on a finger sticking out from the quayside. Vehicles would drive into the module and wait. When ‘Sea Flyer’ arrives she delivers the nodule that she is carrying to another finger, then moves across to straddle the waiting module, sliding it between cabin and hull. She next lowers her cabin onto the waiting module and locks onto it them lifts the module off the finger and is ready to depart on another delivery.

Having devised such a versatile marine vessel it is not unreasonable to add yet another feature, this time a retractable, powered, steerable, undercarriage. Sea Flyer on arriving at a slipway would lower her undercarriage climb the slipway and stop in a parking place, whilst ensuring the cabin is horizontal throughout the operation.

As part of the level sensing and ensuing comfort an inherent benefit occurs during acceleration, deceleration and turning; the cabin will automatically tilt to balance the forces occurring. E.g. if a vehicle has been left without the handbrake applied or no gear engaged, it will not run backwards into the vehicle behind when she is accelerating. Thus eliminating potential insurance claims and keeping the customers happy.

‘Sea Flyer’ is all-electric. This means no CO₂ emissions no contamination of the seas or oceans, no bunkering, no mess no cleaning bills, no smell, no spillages, no slippery surfaces, no accidents and no noise.

Electric motors, actuators, servos are faster acting, more responsive, more accurate and cheaper to run. Just plug it in and switch on, or even collect it from the sun for free.

There is no reason why such a shape should not cut through the water like a knife, especially when Continuous Air Film Emission (CAFÉ) is employed. In which case choose the speed of operation and design accordingly. Speeds up to 40 knots are standard.