If your boat is big enough, consider a built-in refrigerator/freezer from brands such as Dometic, Engel or Isotherm. You’ll find a wide range of sizes and styles, including slide-in units for installations in a cabin or stainless-steel models for exterior galleys. While most marine refrigerator/freezers are AC/DC, some are designed strictly for 12/24-volt DC power.
Since these units dispense with the need for ice, you have more cold storage than with a similar-size cooler. However, most require a shore-power system at the least, and usually a generator as well to provide sufficient juice when the boat’s away from the dock and the main engines are shut down.
Improving cold storage might not seem important until you’re far offshore, and the drinks get warm and the chum stinks. Use these tips ahead of time so you can chill out later.