Wake Images
	SURFACE EFFECT SHIPS (SES)
	An SES has an air cushion that is enclosed by rigid side hulls at its sides, and flexible rubber seals at the bow and aft ends. A "T-Craft" is a transformable vessel that can operate as a catamaran, an SES and an ACV.

	Oncilla
	Cyberiad's hypothetical 1523 tonne displacement vessel "Oncilla" has similar proportions to the T-Craft designed by Textron T&MLS: it is 76 m long and 24 m wide; the air-cushion is 68 m long and 16.5 m wide.
	The figure above shows the predicted wave pattern at 18 knots (corresponding to a hull-length Froude number of 0.34) when the cushion supports 80% of the total weight of the vessel. The minimum amplitude of -2.777 m is found inside the air cushion at about x = -10 m; the maximum of 2.117m is at x = 60 m (about 20 m behind the stern).
	Employing a split cushion system with a judicious choice of sub-cushion pressures can significantly reduce wave heights and wave resistance. In the plot above, the vessel has three equal-length sub-cushions; the pressure in the centre sub-cushion is higher than in the other two cushions.
	It is evident that the split system has radically changed the wave pattern and, more importantly, it has significantly reduced wave heights. The minimum amplitude of -2.429 m is inside the cushion, but it occurs further aft than in the single cushion case; the maximum of 1.183 m is found at about x = 61 m. The wave resistance at this speed is about 1/8th of the single cushion vessel at the same speed.
	The two plots above show the predicted wave patterns at 40 knots (Fr=0.75): the single cushion vessel is at the left; the split cushion variant is at the right. The pressure distribution in the split cushion system that was so beneficial at 18 knots is not effective at this speed. The two wave patterns are quite similar, but the single cushion vessel makes smaller waves than the split cushion, and it has lower wave resistance.
	A split cushion system can be devised that has low wave resistance at high Froude numbers but, in general, it requires high pressures in the fore and aft sub-cushions, and low pressure in the centre cushion. This can be difficult to engineer and more work is needed before a final judgement can be made as to whether it is worthwhile.