The original conviction depended on the judge's ruling that a PWC should be regarded, in law, as a ship, as it complied with the legal definition of "a vessel used in navigation".

The Court of Appeal reconsidered the definitions of "vessel" and "used in navigation". It has now stated, in effect, that although some designs of PWC can be described as vessels, craft which are "simply used for having fun on the water without the object of going anywhere" are not "used in navigation" and thus cannot be described as ships.

Therefore the Merchant Shipping Act did not apply and the prosecution failed.

"The RYA has always advocated that Jetskis and other PWCs should be entitled to exactly the same rights and subject to the same responsibilities as other small craft, " said the RYA's legal and government affairs manager, Edmund Whelan. "This ruling raises a number of issues as to how such craft should be regarded in law."

We understand the Crown Prosecution Service is considering an appeal to the House of Lords and we await the outcome of this with the greatest interest, he added.