Hi Rob,
I'm suspecting lochter would be the best bet although its been a few years since i lived in the 'shire.
I don't think i know of any lochs with a 'wheely boat' unfortunately near Aberdeen but someone might know better than me.
I used to course fish aboyne loch in the past, which was great fun, but i dont know if their accessibility has improved. Might be worth giving them a call and explaining the situation ?
regards
James