Brian, the standard socket at the dock is a standard 15A one.
Searching online I`m surprised no one but Aquavolt has leads on offer. Such a commonly used item I`d expected Whitworths (chandlery chain) to carry them, but no. Public liability concerns maybe, same as Sarca won`t supply the slot shackle they don`t make, and therefore won`t warrant.
You can buy the components but because it is 240v it needs to be electrician wired, (as I think Kurt Kupper of Aquavolt is, I bet he makes them up himself as required). I`ve rewired one or 2 plug ends on household leads, and have an electrical engineer in the family but he`s not a licensed electrician. In part it becomes a potential insurance issue(there`s the old lawyer caution surfacing), I`ll probably buy one from Aquavolt, and be sure. Just surprised no one else seems to sell them.
Island Gypsy 36 Europa "Doriana"