While you were out looking to buy a cooler, you may have noticed that some coolers are labeled as “marine coolers.” What is the difference between a regular camping and picnic cooler and a marine cooler?
Marine coolers are designed specifically to be used outdoors all of the time. They therefore are better capable of resisting the effects of weather, particularly the harsh UV rays from the sun and the blowing sand and salt air by the sea. Sun, sea, and sand can make just about anything degrade given enough time so marine coolers are designed to hold up under these conditions.
In addition to having a more durable exterior, most marine coolers are also treated to better resist odors. This is because they start off the trip full of food and beer and are then later used to store fish that has been caught. While fish are very tasty, they smell, and storing fish (alive or dead) in a camping cooler will quickly have it full of an almost unbearable odor. A regular cooler could be cleaned often to remove the smell, but it is better to have a one which is better able to resist the smell to begin with.
Because they are designed to be more sturdy marine coolers have excellent insulation, allowing even the lower end models to keep ice and drinks fresh for days. However this extra insulation also makes the it heavier, so they are normally meant to be placed in one spot (such as on your boat) and left there for several days. They are not something that you want to lug around while hiking or up and down steep hills.
If you are looking for a cooler to take camping or to carry food back and forth from the grocery then a marine variety is not worth the extra expense. However if you are looking for a cooler to store your fish or to take on a long bumpy boat ride where it will be sitting in the open sun for hours and days at a time, then the marine cooler is what you need.