I have just recently purchased a 1999 sumerset houseboat 16x75 that is on Lake Cumberland in Jamestown Kentucky. I have called Sumerset houseboats to get them to install a purisan toilet system for the boat but they say it is not legal beacuse the length of my boat is 75'. It was my understanding that the law applied to the length of boat that sits in water. For example my boat from front to back at water line is 62 feet. CAN I LEGALLY PUT IN A PURISAN SYSTEM? Can you recommend someone to do the installation in the Jamestown, Ky area. Thanks.

Nope...sorry, you can't.

The legal definition of a vessel length is the LOA ("length overall"), not just the length at the waterline...it's the length measured over the centerline from the foremost point on the hull, excluding any bow pulpits, bumpkins etc to the aftmost point on the hull, excluding any motor brackets, davits or other appendages attached to, but not an integral part of the hull.

So that would mean the length of your houseboat from the bow rail to at least the stern rails...and possibly to the end of your swim platform if it's welded to the hull and not just bolted on....which, if it's more than 65'11", is too long to use a Type I MSD (the PuraSan is a Type I)... but you can use a Type II if you don't want to use a holding tank.

The ManaGerm from Raritan is a Type II, and therefore legal on your boat. You can read all about it on the Raritan website at http://www.raritaneng.com