I booked directly with the boat owner, Des, back in 2011, and he even let me park my bike in his storage building near the docks during the day, and change back into bicycling clothes there afterwards, so he did go to extra lengths. Maybe I’m just cheap, and I thanked him profusely, but didn’t leave any extra tip. Des was on the boat, but he had another man operating the boat ... not sure who was the “captain” in that case, but maybe two tips would’ve been given.
The visit is mostly climbing a lot of rock steps, with an opportunity to wander into the grass on a flattish place part of the way up, and then to walk amongst the beehive-shaped stone huts at the top. Sturdy shoes with good soles will do the job (I wore mountain bike shoes), so heavy-duty hiking shoes aren’t absolutely necessary. I hope the water’s calm enough that your tour goes- it’s an amazing place!