Rotomolded coolers are overkill for a day at the beach.

The short answer: rotomolded coolers are tougher and hold ice longer because they’re made from a single thick piece of plastic with no seams. Injection-molded coolers are two hollow shells glued together with foam in the middle. That seam is a weak point — it can crack, let air in, and lose insulation over time.

Rotomolding (rotational molding) spins a mold full of plastic powder while heating it. The plastic melts and coats the inside evenly, creating one solid, seamless wall. No glue, no hollow cavities. This lets them pack in thicker insulation — often 2-3 inches of closed-cell foam vs. the 1 inch or less in injection-molded coolers. More insulation means ice lasts days longer.

But here’s the tradeoff: rotomolded coolers are heavy, expensive, and hard to carry. A decent one costs $200+. An injection-molded cooler like a basic Coleman handles a weekend trip just fine and costs $40. The rotomolded advantage only matters if you’re camping off-grid for a week, running a tailgate in direct sun, or regularly dropping the cooler off a truck bed.

If you only cool drinks for a few hours, save your money.