Whiskey Class Soviet submarine
The Whiskey class boats are basically modified versions of the German Type XXI U-boats. The German subs were 1,600 ton craft, and actually more capable than the 1,100 ton Whiskeys. But that's because the Russians just wanted a good, basic diesel-electric submarine for post World War II use. They got it with the Whiskey, and built 236 of them. The Whiskeys offered here are demilitarized (torpedo tubes sealed and torpedo handling gear removed, along with other military equipment.) That leaves a lot of room for entertaining. Normally, a crew of 54 runs a Whiskey class boat, but about half as many would be required for a civilian version. While it is possible to refurbish a Whiskey as a pleasure craft, you would still end up with a boat that provided a rough ride on the surface. Running submerged gets old real quick. Perhaps you could just tie it up at a dock, gut the interior, and turn it into a party room. Not much chance of criminals buying one of these for use as a smuggling craft. The Whiskeys are notoriously noisy and easy for warships and anti-submarine aircraft to detect.