Rotomolded coolers are the only choice.

Yes, for a week on the river you want a rotomolded cooler – the thick plastic, heavy insulation, and rubber latches are what keep ice for days, not hours.

Cheap coolers (igloo, coleman) lose ice in 2-3 days, even with pre-chilling. Rotomolded ones hold ice 5-7+ days if you do it right: freeze everything solid first, pre-chill the cooler, use block ice, minimize opening, keep it in the shade. Brands like Yeti, RTIC, Pelican, and Orca all work similarly – the main difference is price and lid design. Yeti is the most expensive but has great customer service. RTIC is almost as good for half the price. Pelican is bombproof. Orca has a nice drain plug. Pick one that fits your boat (usually 45-65 quarts for a group of 4-5).

Key features: thick walls (2-3 inches), freezer-grade gasket, heavy-duty latches (preferably replaceable), a molded-in drain plug, and tie-down points for strapping it down in the raft. Don’t get a cooler with wheels – they’re less durable and waste space.

Your trip will be better when day 6 still has cold beer.