Jet Ski rentals can be found all over the coast, starting from Oliva, in DENIA are various companys, in Javea of course, not ofered on the Benitachell Beach (thanks God..), naturally in Moraira, in Calpe, in Campomanes/Mascarat, in Altea, not sure about Albir, and of course in Benidorm and Villajoiosa!
In the other villages is jetski rentals sometimes at the beach in summer, more to be published when the season approches
Generally can be said, that due to my last infos, jetski cannot be driven by yourself without a proper driving licance – if you take a rent, there will be someone from the compnay with you at all times on his jetski
Many of the companys offer routes, like from DENAI to JAVEA, From there around the CABO LA NAO, from MORAIRA to CALPE, from CALPE to ALTEA and so on
Quiet a number of people (especially FRENCH) bring their Jet Skia along with them in summer, and make the sea busy out there, swimmers, kayakers, paddle surfers, divers etc look out, accidents are happening easy!