Let’s say that you have a large boat. You cruise up to a tropical inlet, but you’re not sure if the water is deep enough for your cruiser. You want to go ashore, but how do you get there? You use a smaller boat—your dinghy
—to go from the big boat to the shore.
A little boat that runs back and forth to a bigger boat (or ship) is called a tender—because it tends to the needs of the larger craft. Moderately sized recreational boats call their tenders dinghies.
A dinghy can be as simple as a rowboat, or as high-tech as a twin-engine rigid hull inflatable
—it all depends on the size of the mother ship and the preferences of the owner.
Dinghies are often used to take crew members ashore for supplies, or run other errands, leaving the big boat moored out of the way, in the harbor.