We use the PET folding toilet on our M17 and I recommend it! It folds up small enough to stow in the bilge area under the cockpit (we keep the anchors in a bag under there too). The WAG bags used with it are somewhat expensive (around $2 each or so) but they are double sealed and have no odor leakage (although I wouldn't leave them on the boat for weeks!). I have to say, it sure beats having to dump out a porta potty. The bucket idea would work, but might not be as comfy and I don't think a bucket would fit in the relatively small bilge area in an M17. The PET toilet seat is full size...perfect for enjoying browsing the tide charts as you complete your business. Rick