There are two excellent rowing machines in Agia Efimia harbour.
One is called Jungle Cat and the other is called Pink Panther. (currently still under repair)
Loosely termed as "Catamarans" at least one of them floats at the moment! Neither have a working engine between them (That's none out of a possible 4 engines
) the sails are crap and need replacing, so a couple of oars is the only viable alternative really!
Suggest you go for Jungle Cat as Pink Panther repairs have now made one keel at least a foot longer than the other, and the twin rudders are no longer the same shape, so you could end up going in circles and getting nowhere fast!!!