If it has a holding tank, portapotty, composter or any other device that's designed to receive and hold but NOT discharge human body waste, it has a Type 3. If it has a Lectra/San, ElectroScan or PuraSan (the name will be on it) treatment device , it has a Type I. Most boats that have treatment devices also have a holding tank. It would not have a Type II...those are treatment devices for boats over 65'.
It appears you're kinda new with boats big enough to have a sanitation system...in which case I think you'll find my book (see link in my signature below) very useful. The title is a bit misleading...although it does deal with every source of odor on a boat and how to cure, or better yet PREVENT, 'em. it's actually a comprehensive "marine toilets and sanitation systems 101" manual that explains the laws, describes all the types of systems and will help you learn how to operate and maintain your system to prevent 90% of problems instead of having to cure 'em. 'Cuz you get to do any preventive maintenance on your terms when it's convenient...the need to cure a problem NEVER happens when it is!
And I'm always glad to answer any questions it doesn't.
--Peggie
"If you can't explain it to a six year old, you don't completely understand it yourself." --Albert Einstein