The 5O5 is a double-handed boat that incorporates a light weight, high performance hull design with a powerful sail plan and one trapeze. The boat is unique in that it has outstanding performance in all conditions. In light air it is quick and responsive, and in breeze it just goes faster. Planing begins in 10 knots of wind.
The Class Rules are One-Design, with the emphasis on controlling aspects that most directly affect boat speed. The sail plan and hull shape are tightly controlled, while the rigging layout, spars, and the foils are open. This allows the boat to be set up in many ways to suit the sailors; there are several distinct types of sail and layout combinations from the US, Australia and Europe. The result is that, at any Worlds, all the types will be used by the top 10 finishers, and usually by the top 5. Most US boats currently have adjustable shrouds, forestay, and mast ram, which allows rig tension, rake and bend to be changed while racing. There are many ways to rig the boat; it still takes the best sailors to win.
Hulls are built of either fibreglass/polyester or of epoxy resin/Kevlar and honeycomb composite. Both types are equally competitive when new, but twelve year old epoxy composite boats can still win major championships.