I thought this sounded like a great idea when I first got into catamarans. I bought a brand new 1.5 hp outboard and made a mount. I think I used it once before I sold it. It's just too much trouble and weight.

You can sail through some pretty narrow stuff with a little patience and skill. Can you not hoist sails at the dock and just go sailing?

The torqueedos are a neat product...I've been looking at them for my monoslug (can't convince myself to leave the weight of the outboard on the stern so I have to heave that thing all over the place). You'll need to really check on the waterproof nature of the Torqueedo, though...we all have the capability of flipping and going turtle and I can only imagine what might happen if the Torqueedo (and it's lithium batteries) aren't up for the submersion challenge. A gas outboard is not going to enjoy that either.

One other consideration might be to find a used dingy with an outboard (or trolling motor) and use that to tow the cat out. Park the dingy on the beach and go sailing. It probably wouldn't cost much more than a new 2 stroke outboard if you shop around a bit. Heck, you can build a nice sized pram out of two sheets of plywood.