Selecting the Right Dinghy for you - the Three Steps

by West Marine/Sail-World Cruising on 2 Jan 2009 How do you select the boat that best meets your requirements with so many available choices? After all, some of your best memories just might come from the dinghy. There are three main steps:

1. Choose the floor construction that best balances portability and performance

2. Select the right fabric for the locations where you’ll use the boat

3. Buy the biggest boat that fits within your budget and space requirements
Floor Construction and Boat Category


1. The Right Floor:
An inflatable’s floor construction is the key to the trade off between portability–ease of assembly and compact storage–and the rigidity needed for best performance. A rigid deep–V hull made from composite plastic, fibreglass or aluminum–a Rigid Inflatable Boat–is an efficient high–performance planing hull, but RIBs often must be stored on a trailer or set of hanging davits. Boats with more flexible fabric floors fold to a light, compact shape, but their flexibility extracts a performance penalty. If you want your boat to plane, allowing you to exceed 5 mph, a semi–rigid floor is required.

Soft–Stern Dinghies:
These economical boats, like the Mini Dinghy and the Micro Dinghy, are very easy to set up and can be stowed in very little space. They are best suited for beach fun and short–range exploring in protected waters, fresh water fishing or camping. Their floors are inflatable, and don’t need to be removed for storage. Powered by oars or a small electric trolling motor, these 'donut boats' are the most basic inflatables at the lowest cost.

RollUp (RU) Boats:
Like dinghies, these boats have floors you don’t have to remove when stowing the boat. Rollups like our RU–260, a 'classic' that is back by popular demand, can be unrolled, inflated and launched in minutes. Floors use wooden slats enclosed in fabric pockets, and you don’t need to remove them for storage. Rollup boats have a transom, so you can use a small outboard motor. Rollups excel as tenders. Their flat bottoms and small engines (up to 4HP) make their performance non–planing, limiting their range to in–harbor, relatively flat–water travel.

Sportboats:
Sportboats are inflatables with a removable rigid floor system made from plywood, composite plastic or aluminum. The floor assembly is made stiffer with the addition of stringers, which run fore and aft to hold the floorboards in alignment, and aluminum extrusions to hold the edges in position. With the floorboards assembled and the port and starboard hull chambers and small tapered keel tube inflated, the boat’s floor fabric is stretched taut and takes on a shallow V–shape. This enables the boat to ride through chop and track in turns better than a flat–bottomed boat. The floor also makes sportboats heavier than dinghies, but these boats are fast and lively with outboards from 6–25hp and offer a great performance for the price.

High Pressure (HP) Inflatable Floor Boats:
Take a sportboat, such as the Wood Floor 275 or 310 and trade the wood floor for a high–pressure inflatable floor, and you have an HP Inflatable Floor boat (sometimes called an Airfloor boat), combining the performance of a sportboat with the light weight and compact stowage of a soft stern dinghy. Its special high–pressure inflatable floor (pumped up to 11psi) is substantially lighter and when deflated, can be rolled up right inside the boat. We have been astounded at how quickly inflatable floor boats jump on plane, and the fine performance they achieve using only a small outboard, thanks to their low weight. For example, our 60lb. HP 310 will plane with one person using only a 5hp outboard. The boats flex just enough to absorb wakes and waves that would threaten to throw you out of a hard–bottomed boat. While slightly more expensive than conventional sportboats, HP floor boats are a brilliant combination of benefits, not a compromise. And the setup time is very short!

High Pressure Inflatable V–Hull (HP–V) Inflatables:
Exclusive HP–V floor technology is the next evolution in floor construction for 2008, creating boats that perform more like a RIB, with one’piece (non–removable floor) configuration–the simplest high–pressure rollups ever developed. A further evolution of the HP Inflatable concept, HP–V floors dispense with sausage–shaped inflatable keels. Inflated to 11psi with two Halkey Roberts valves located in the bow, the V–shaped integral floor is rigid, with enough shock–absorbing flex for great performance and a smooth ride, just like the flat–floored HP inflatables above. Cargo is located further down than in a flat–floored boat, and the low center of gravity provides stability comparable to a RIB hull design.

Rigid Inflatable Boats (RIBs) or Rigid Hull Inflatables:
RIBs offer the 'real boat' performance and strength of a rigid moderate or deep–vee hull. Their fibreglass hulls carve turns and cut through chop like conventional boats and shrug off abrasion from cruising gear, sand and gravel, dive tanks, etc. But unlike conventional boats, the addition of inflatable tubes to the topsides makes them more stable, more buoyant and less likely to scar the topsides of other vessels when used as a tender.
Their lack of portability is the price you pay for a RIB’s performance. The hulls cannot be disassembled, and therefore you can’t stow your RIB in a bag in the lazarette. You can deflate the tubes and stow the boat on deck in far less room than the inflated boat, but it still takes up space. Therefore, we generally recommend RIB's for owners who either intend to stow their dinghies inflated on deck, on davits, or deflated and lashed on a weather deck. Their light weight also makes them a cinch to trailer on a light–duty boat trailer.

Compact or Folding RIBs:
Compact RIBs have a hinged folding transom, which allows the boat to be stored in much less space, and are super portable–we're talking roof rack to water in just 10 minutes! The hull is made from either fiberglass or RIMTEC injection–molded polyester, and has a shallow V–shape. The transom is a plywood sandwich that is firmly bonded to the inflation tubes. A flexible fabric hinge connects the floor to the transom, allowing the transom to fold flat when stored. A large zippered bag is included for storage, and the stowed boat looks like a giant surfboard in a travel bag. While still large, the Compact RIB will fit on a foredeck or under a boom much more compactly than a normal RIB. It also fits nicely on vehicle roof racks or in the back of a station wagon.


Catamaran Tunnel Hull Sportboats:
Twin–sponson sportboats provide the ultimate in inflatable performance. Advanced Cats and their close relatives, the Sport Cats from Advanced Marine Inflatables, are descendants of high–speed surf rescue boats first used off the coasts of South Africa in the early 1980’s. These rescue craft could hit speeds up to 65 mph, and handle extremely rough seas and breaking waves. Sport Cats are raced as two–person one–design ZapCats in the UK and Europe, as ThunderCats in South Africa, New Zealand and Australia, and in the U.S. on the A.P.B.A Inflatable Tunnel Hull Race Circuit. Imagine an aquatic NASCAR, or Google the above references and prepare to be impressed. The Advanced Cat models are a drier, more traditional version of these amazing boats.

Take a flat–bottomed sportboat, and add two wedge–shaped sponsons constructed with high–pressure tubes and custom’molded high–density rubber. The resulting tunnel hull creates lift for efficient planing and also provides a cushion of air for a smoother, high–speed ride. The wedge shape provides a good 'bite' on the inside of a sharp turn while the outside sponson slides over the water, preventing tipping or flipping. As a result, the boat can perform extremely tight turns, even at high speed (a Sport Cat can reportedly pull 2 Gs of cornering force!). Oversize main tubes and increased beam allow for greater load bearing and stability.

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