Help with plastic hydrohoist

Gents, I have a hydrohoist lift and I can hear a small leak in one of the blue plastic "pontoons tanks". The leak is under some structural metal and when I take it apart, the sound and bubbles go away. Therefore I have it narrowed down to a small area but not pinpointed. For you all knowing gurus, what is my best patch material for this blue plastic? I'm dreaming of something like epoxy that I could spread on the whole area where the leak is. Flexseal As Seen on TV is one thought but I'm not sure it will adhere to the plastic (I am a doubter of this product but it would be perfect). What say ye?

I barely know anything about Hydrohoists.    I've always assumed the tanks were fibreglass.
You would probably be just fine with F/G Mat and either epoxy or poly resin.   Clean, clean, clean then sand the repair area.
But, give it a day or two, surely someone here has been thru the same issue.

Thanks. I confirmed this morning that they are HDPE. Plastic welding is best but their tech support suggested that I start by trying MR Stickys. It looks like an epoxy and they said they have had good results. Said to try first due to cost and also suggested an alteration to my lift. Need to cut a metal bar down a couple of inches. So I'll be equipped with my recip saw, some files, rubber end caps for what I'm cutting and some MR stickys. I'll also take a dremel to clean up around the area.

I would certainly trust the manufacturer's advice. Having owned aHydro Hoist (2 different models) for twenty years I can tell you that the company knows what they're doing and have never let me down. An excellent lift if you live on a reservoir with 5-6 foot level swings daily.