Am an experienced builder. Looking for recommendations for my first seaplane with floats​. Preferably 1st class scratch built plans. Nitro powered in the order of 80" wing.
Open to any/all information on buildin/flying off water. I hate reinventing the "wheel".

By the time I get to 80" I am courting gasoline and not glow fuel.

Do you want scale, sport-scale, sport or just something that lands on water?

If I were building from plans for an 80" floatplane I'd be checking out a PC-6 Porter. I've been flying a 50" version (on floats) and it would make a wonderful gian scale project.

so not what you are proposing but IMO

the best first float plane set up with ease of build....Goldberg Cub and Goldberg float kit with a 70FS. Perfect no brainer easy to build, set up already designed, great flyer at 76". I have had a couple. very durable as well.

if gotta have larger, hard to go wrong with Cub on floats.

if being first seaplane, start with something that you do not have a ton of time and money invested.

my thoughts

If you want an excellent first floatplane without huge investment I'd suggest the Durafly Tundra. I am very impressed with mine. It's a fair sport flyer and a very capable float plane.

It's also semi-scale based on the Highlander STOL from Wild West Aircraft. They have a dead stick take-off on their webside (airplane rollling down an incline & off a cliff tales off!). It will teach you float flying and be a joy thereafter while you build for around the price of three good giant scale servos.

I have this DH-2 Beaver from Hobbyking and it flys off water very well. It's close to 80" span. I am using an OS .70 four stroke engine and it provides plenty of power.
http://www.hobbyking.com/hobbyking/s...00mm_ARF_.html

These are the floats I'm using. http://www.hobbyking.com/hobbyking/s...lsa_930mm.html

The big question is, "Will it be for water only", If it is you'll want a flying boat.I have been flying off warer since 1969, So I have lots of info, But I need to know what direction your going.