They will float up on you. Unlike wood, which will sink after it gets waterlogged, plastic pallets wont.

Will a pallet float?

Lots of us use pallets for structure – general purpose or FH spawning in shallow water. If you just put them in the water, they will of course float.

Are plastic pallets good?

In industries where sanitation is a concern, like food and pharmaceutical products, hygienic plastic pallets are the preferred choice. These pallets have a much longer lifespan than wood pallets as well. They’re more durable and less likely to break down on repeated trips. It is the ideal platform for re-use.