Buoyancy
Consider buying a boat fitted with in built buoyancy or have extra buoyancy installed.
Many smaller boats are built with buoyancy and are said to have positive flotation. This is a technical term meaning the boat will stay upright when filled with water and will support the weight of passengers, equipment and the motor. In built buoyancy is also possible in larger fiberglass boats however it must be requested before manufacture. 
The benefits of buoyancy are:
* the boat will stay afloat when capsizing or swamping happens 
* passengers can stay with the boat until help arrives 
* provides shelter and gives more time to activate emergency procedures 
if the boat stays upright, it provides an opportunity to bail water out of the boat.


( an excellent web site which discusses adding flotation to a C22 )

http://sites.netscape.net/tedsailingpage/Floatation.html