Over the years I have used various types of yacht tenders. Some have been for access to yachts while on their moorings; others for towing while cruising as a means of getting ashore on arrival, and a couple of inflatable dinghies as substitute life-rafts.
They fall into categories by virtue of their design:
Access to Yachts while on their Moorings
Most of mine were 8 to 10 feet long with high topsides to facilitate carrying loads and to prevent spray coming aboard while rowing or when using an outboard engine. Some were fitted with integral buoyancy compartments, whereas others needed buoyancy bags. Nearly all of them were large enough for three adults. Their construction was either glass-reinforced plastic or plywood.
Dinghies for Towing while Cruising
These were similar to the above, although once in a while I towed a Seahopper folding dinghy which was usually stowed in the cabin. Some of my inflatable dinghies were towed, but strong winds would occasionally flip them upside down. I discovered that unless an inflatable dinghy was drawn up tightly to the stern of the mother ship she would cause drag, which slowed the yacht down. Because of this drag effect, inflatable dinghies can interfere with the tacking process. For long passages they are best partially deflated and kept on deck for immediate use.
Tenders as Back-up Emergency Life-rafts
A few tenders are purpose-built to serve as life-rafts, but they are expensive and unwieldy; this is due to their heavy construction. For those who do not want to cross oceans, an ordinary good quality inflatable dinghy makes a serviceable life-raft, providing she is equipped with survival gear. A genuine life-raft can be deployed rapidly, simply by tugging a painter, but a substitute inflatable dinghy needs to be manually inflated. Another alternative is to use one of those ingenious dual-purpose tenders made in two parts for compact stowage.
Through hard won experience I have come to prefer inflatable dinghies similar in type to the Avon Redstart, capable of carrying three adults and their gear.