This is a broad topic. Many will have other opinions than those expressed here. Keep this in mind as you put this information into practice. We only have experience with inflatable dinghies so we will not discuss hard dinghies.
- Before you select a dinghy you need to determine your needs, stowage capabilities and budget.
- Do you need to go fast or are you patient?
- How many people will you haul maximum?
- Are you Earth First or Pocketbook First?
- Do you have room on deck to store the dinghy fully inflated and secured for passage?
- Do you want a wet ride or a really wet ride?
- Do you prefer low price or low cost?
- Are you made of money? (the big boat will soon solve that problem)
With an idea of your requirements we can begin to look at the options.
- Planing versus displacement inflatables. OK, there aren't really full keel inflatable but some boats with soft floors will have trouble planing with a load. The classic Avon Redcrest falls in this category. It is a tough inflatable with a long life so many are seen on the used market but don't plan on speeding in a 5 mph zone. Dinghies with slat floors and no inflated V also fall in this category. The key to planing in stiffness in the floor, strength in the transom and horsepower. A rigid bottomed inflatable is best for speed but plywood floors are also good and, surprisingly, inflated floors work pretty well.
- Hauling 2, 4 or more. Cruising boats seem to be crewed in increments of 2 plus or minus a few kids (minus?). You may want to get a dinghy which just accommodates the crew or you may want to also transport guests or fellow cruisers. To plane with 2 people you will need at least 8 hp and 15 hp will get 3 on plane but you usually need more to get 4 on plane. Outboards usually use one motor design for a pair of horsepower ratings like 9.9 and 15. The importance of this is that they will weigh about the same. Wrestling the outboard on and off of the dinghy is the hardest part of assembly so it is best to get the highest horsepower to weight ratio possible. Of course, if you are slow and steady type you can get by with a small motor. It is still best to avoid the 2 to 3 hp motors because they suffer some reliability problems but 3.5 to 5 hp motors are inexpensive to buy and operate. They are also light.
- Save the planet or the budget. Four stroke outboards are now available in all sizes and the offer some advantages and disadvantages. On the down side they are heavier and more expensive. They also require more complex maintenance and parts are not easy to find in remote areas. They can also be more difficult to clean if you submerge it in salt water. The positives are that they require maintenance less often, they use significantly less fuel and they are much kinder to the environment. The last point is key because it needs to be important to you to tip the scale. 2 strokes are still the norm in most of the world. Even with high fuel costs the 4 stroke has a hard time paying for itself. The added weight will be dreaded each time the motor is attached unless you have a good lifting system. Future 4 strokes will get lighter and easier to maintain but at the same time 2 strokes will get more fuel efficient with reduced emissions so the market will sort itself out over time and for now you must choose from the technology available. Yamaha Enduro series are the most popular outboards worldwide but they are not available in the US. They are usually available in your first foreign port of call so consider a stopgap solution and pick up a new outboard when you get to the tropics. We carry our normal outboard and a 2.2 hp as backup and in harbors with a short run to shore.. Mexico and parts of the Caribbean are not so great for outboard shopping but Venezuela, Cook Islands and Fiji have some real bargains on new outboards.
- If you have the room for a fully inflated dinghy of 10 plus feet stored upside down on deck then you have all of your options available. If you can't store an inflated dinghy but you can handle an 8 foot surfboard facedown on deck you still have many options. If you can only handle a big suitcase then there are still possibilities. If you don't have this much room you need to take a truckload of junk off of your boat and to the next swap meet, no wait, you'll just come back with more. An inflated dinghy on deck is considered a safety option by many cruisers. Room for the dinghy means that you may choose a rigid bottom inflatable or RIB. A RIB has inflated tubes around a rigid hull of fiberglass or aluminum. The rigid hull offers many advantages including durability, better performance in rough conditions, dryer ride, and the ability to handle higher horsepower outboards. The big disadvantages are weight, cost and inability to fold up. Some RIB's, mainly the aluminum models, have the ability to deflate and fold the transom leaving a package the size of a short windsurfer. If a RIB isn't possible then a fold-up or roll-up boat is next best. The floors are either plywood, wooden slats or a special inflated sandwich. Plywood floors are the stiffest but they are the heaviest and they are more difficult to assemble and breakdown. Slat floors are cheap, light and easy but they don't work get on plane or perform well. Inflated floors are the best compromise in this category but with the caveat that you have to be careful about punctures and sun damage to the floor. The last option is to get a dinghy with just a rubber floor like the Avon Redcrest. This is the best on price, size and ease of use but forget planing.
- To make your dinghy ride as dry as possible you need the biggest tubes you can get. On RIB's you should also look at the the shape of the hull and get first hand feedback but in general the higher you are the dryer you stay. Large tubes also give the boat more strength and provide a greater sense of stability. They are harder to board from the water and they are usually more expensive. Tube size will increase with boat size but favor boats with bigger tubes.
- PVC boats cost less but there is a reason. PVC boats breakdown in the sun. Our PVC dinghy is showing signs of sun damage after 2 years. This can be reduced with sun covers and special paint but it will be a constant battle. Hypalon boats are much more resistant to sun damage. Unfortunately some manufacturers are little confusing on the use of Hypalon in their boats so you need to be careful about their claims of Hypalon content but a quality Hypalon boat will last 10 years in the sun when a PVC boat will be looking ragged after 3 years.
- If you are still working while getting ready for the big adventure then you may be spending money like a drunken sailor. If the budget is a secondary consideration then get a name brand Hypalon RIB. If you are budget conscious and are willing shop around then we feel the best deal in the RIB category is the New Zealand made Auqasport. It has an aluminum hull and large Hypalon tubes but we have seen sun damage to stitching in the sun cover and deterioration in some of the extras. A 10 ft boat costs under $1,700 US$ in New Zealand. For the cheap solution a used Hypalon boat would be the way to go but have it checked by a professional before you buy.