you can rent Lasers and cats at some of the beaches in Protaras and Ayia Napa. this is the easiest way.
alternatives are yacht charters - try http://www.interyachting.com.cy/fleet/fleet.htm - or, for a nice day out and some stunning scenery, hire a little motorboat and head 'round to Akamas and Latsi, north of Paphos. You can get all the info you need on this by just wandering along toward Paphos port.