Can I use plastic bottles/jugs as flotation?

[Captain Ahab]

I can't remember where, but somewhere I saw where a guy put the bottles in the compartment then poured expanding foam around them. Objective was to save on the amount of foam needed.

Just make sure you use closed cell foam - open cell foam (do a search here lots of info) will absorb water making your boat really heavy and will not help with the intended purpose

 

[LDUBS]

I can't remember where, but somewhere I saw where a guy put the bottles in the compartment then poured expanding foam around them. Objective was to save on the amount of foam needed.

Just make sure you use closed cell foam - open cell foam (do a search here lots of info) will absorb water making your boat really heavy and will not help with the intended purpose

Yep, otherwise you might as well pack the space with a bunch of wet beach towels.