I got my Avon tender free when I bought my first boat, White Roostar, about twelve years ago. The owner, a dentist, had come down to Yarmouth on the Isle of Wight to hand over the keys, plus any items on the inventory which were not on board. Having driven down from the Midlands he realised that he had forgotten the tender, so he walked into the chandlery and bought me a brand new one. I always thought dentists got paid too much.....
I don't know whether I would have bought a brand new Avon myself, but I've become a tremendous fan. After a dozen years of quite hard use it has not a single patch, stays as tight as a drum and, functionally if not cosmetically, is as good as new.
Its only drawback is that it has a separate outboard bracket rather than a rigid transom. This restricts the size of outboard you can use, and means that you can't lock the motor on securely. It also means the tender is more likely to flip over in gusts, particularly with the motor on. Get a tender with a rigid transom if you can. If you can stow it, a small RIB would be great. A lot of people seem to buy Caribe or AB RIBs in Venezuela, where they are (or were) comparatively cheap. They tow them around while in the Caribbean, then lash them on the coachroof (or sell them) when leaving.
We decided that it was important to have (at least) two tenders so that we could go ashore independently. I would recommend this to everyone, married or not.
For our second tender we ended up getting an inflatable canoe, about 10 feet long and made by Metzeler. We bought this secondhand at a boat jumble, for $20 I think, and it needed a bit of patching to make it reasonably airtight. It was a great success. Not only was it a useful second tender, which could be lashed fully inflated on the side deck, it also doubled as a washing tub for clothes, and as a bath. It wasn't much good as a surfboard, though. Sadly, after a year's hard use it started leaking again, and eventually had to be disposed of. I'd seriously consider getting another.
DO get an outboard for your tender. You don't have to use it all the time (it can be pleasant to row) but there are times when you'll need it. There are many places where you will have to anchor far offshore, and rowing a loaded inflatable into a 25 knot breeze can be tiring and may be impossible. Most of the boats that set out without an outboard bought one later, often at greater cost or of poorer quality than they could have got at home. In the meantime we were frequently seen towing convoys of three or four tenders across harbour.
Much is written about the need to secure your tender, but during our year's cruise we found less of a problem than we expected. It is more common, in our experience, for a tender to drift off due to a badly tied knot than for it to be stolen. This happened to us, and also to some friends of ours. In both cases we got the dinghies back. When dinghies are stolen, or indeed when boats are boken into, it is usually through their owner's not taking basic precautions, and abandoning them in one place for long periods. Finally, when dinghies are stolen it's more likely to be by another yachtie than by a local.
A word about Tinker inflatables. These have many good features. They are a delight to row compared to any other inflatable. They zoom alon on the plane with quite a modest outboard. You can even sail them. Sadly, though, they don't seem to cope well with tropical conditions, deteriorating fast. For that reason I could not recommend them for use in the Caribbean. Also, their low bow and spraydodger have disadvantages both in terms of shipping water, and in disembarking from the bow at a crowded pontoon.
The outboard we set out with was a Mercury 2.2 which we bought cheaply secondhand, but obviously little used, in the UK. Be sure to take out at least spare plugs, impellers, points (if used) and shear pins for your outboard. The motor was on the whole excellent, until it had a dunking off Canouan. After that it became rather temperamental. Following another dunking in Tobago recently, the Mercury went on long-term strike. We sold it and now have a 2 hp Yamaha, which starts first pull but seems noticeably less powerful.