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Choosing an Inflatable Dinghy

Choosing an Inflatable Dinghy

Choosing an Inflatable Dinghy or Tender


What will be your "Tender to ____"

This article looks at inflatable dinghies as a tender, but you could choose the nesting dinghy which is a solid pram type which can be stored on deck. You could also choose a kayak or small sailboat.

We are focusing here on boats inflatables under 11ft. larger inflatables, RIBs and Tenders are a whole new subject.

Before choosing a dinghy you must prioritize your needs/requirements

  • Capacity; number of people to carry or payload
  • Performance; are you going 4 knots or want to plane and go fast
  • How far will you go; An inflatable works well for short trips & sheltered conditions
  • Propulsion; Will you use an outboard or use oars
  • Portability; Do you need to carry or lift the dinghy
  • Storage; Roll up inflatables can fit in a locker or lazarette
  • Cost; Higher priced models are made from Hypalon which lasts longer

Dinghy Storage


Red Start

Storage is the biggest issue with a Dinghy. Most people will tell you to get the biggest Dinghy you can afford and have the space for.

Storage options include; storing on deck, roll up and store in a locker, storing on a swim platform, Storing on a set of davits or just towing.

A typical first level inflatable will fully deflate, and fits in a special valise which can be stored in a locker. Check the size of the valise against your locker dimensions for fit.

The other option is to partially deflate the dinghy and fit into a space on deck, which does not interfere with day to day boating or sailing activities.

Typical places to store on deck include the foredeck over a hatch. The next may be over the main hatch companionway. For a sailboat just aft of the mast and under the boom may work.

Towing a dinghy is a whole new subject as are Davits and Swim platforms.

Types of dinghy


Red Start

Once you have figured out your needs you can next choose between an;

  • Inflatable
  • roll up
  • RIB

There are many names associated with inflatable dinghies. They are called RIBs, rigid inflatable boat, rigid bottom inflatables, hard bottom inflatables, soft bottom inflatables, wood floor, inflatable keel and more.

Each are modifications of the same thing, which is the inflatable tube. The inflatable tube not only allows for deflation and storage it also acts as its own fender so you will not have to worry about coming alongside.

Tubes also offer lots of stability, it will be much harder to capsize an inflatable than a solid dinghy. The tubes also add lots of additional buoyancy so you will not sink.

The true inflatable can be fully deflated and rolled up into a bag and stored into a locker, or partially deflated and stored on deck.

Pictures above Avons Redstart.

There are many upgrades to the inflatable concept, including solid transoms, solid floors, inflatable high pressure keels, high pressure V bottom etc. All these upgrades are meant to increase performance, speed, directional stability etc. These do come at the sacrifice of storage space and weight.

The next step up is a RIB. The RIB has a fiberglass or solid V bottom. This gives the boat much better planning and directional stability. The sacrifice is storage and weight.

A RIB needs to have a davit, a dinghy garage or a swim platform or can be towed. Many powerboats have swim platforms and so RIBs are more popular. Sailboats unless you get big enough do not have sufficient storage for a RIB. Larger sailboats above 40 feet are getting to the point of being able to add davits and sailboats over 60 are starting to have dinghy garages.

Types of inflatable Dinghy

 

Example

Inflatable roll up

Mostly powered by oars. The first thing you will notice with a true inflatable is the bottom. The bottom is mushy and flat which means walking around is limited, but its small. The bottom does not give any directional stability, maneuvering takes some skill

The Avon Redstart is one of the most popular inflatables.

Inflatable roll up with slatted floors

The addition of the floors makes standing up easier, which helps boarding.

 

Inflatable roll up with plywood transom

The solid stern makes for a much more robust mounting for an outboard

 

Inflatable roll up with HP inflatable floor

Instead of slats or solid floors, inflatable floors offer a rigid bottom

HP-275 & HP-310 High-Pressure Inflatable Floor

Inflatable roll up with inflatable keel

An inflatable keel give some directional stability due to the underwater shape. Not as much as a RIB bottom but much more than a flat bottom

Zodiac Air lite range 260

RIB

RIBs have solid shaped hulls, which are faster, have higher load carrying potential, and better directional stability, but cost far more and are heavy. Best suited for powerboats with swim platforms or davits.

The Walker Bay Genesis RIB is 11ft

RIB with folding transom

These folding transom RIBs are meant to bridge the gap between an inflatable and RIB, by allowing deflation and folding in the transom. to reduce storage needs, but still keeping the solid V bottom.

Avon Rover 310 Lite

Catamaran type

Catamarans offer more performance than an 100% inflatable and have equivalent payload and directional stability as a RIB.

The Dux Yacht Tender can plane yet is much lighter than a RIB.

Dive boat inflatables

Not your average bear the Patten is an example of a custom inflatable

Patten

Inflatable Materials & Construction

Tube construction

The most common materials used in inflatables are PVC coated nylon or polyurethane and neoprene coated with DuPont’s Hypalon. PVC is popular with cheaper inflatables, while the Hypalon is more expensive and better at protecting against UV. Hypalon coated fabrics are generally glued while PVC lends itself to welding seams together.

Hypalon is more expensive, but gives the fabric extra durability and protection from the sun. The Hypalon coated fabric is more flexible than the PVC coated material, making it easier to fold. The flexibility of the fabric ads to durability.

Typically a Hypalon tube will get a 10yr warranty and PVC tubes 5 yrs.

Inflatable Materials & Construction

Floors



The original inflatables just have the tube fabric/material forming the bottom. This works fine, except it is hard to stand up, and the flat bottom prohibits fast speeds and directional control.

The first upgrade is to add plywood, fiberglass or aluminum slats to provide a solid surface, which helps standing up.

Many newer models have air floors which are inflatable floors to ad rigidity, but without the weight and extra parts of slatted floors.

Air keels inflatable keels. Still formed out of fabric the inflatable keel gives the bottom some shape. The slight V shape gives much more directional control and the potential for higher speeds. Inflatable keels can get close to the shape of a RIB bottom, but cannot form as deep a V.

The image show a Zodiac model with inflatable keel

Inflatable Materials & Construction

RIBS



RIBs have the hull bottom made in fiberglass or injection molding to provide a planning surface with a V shape that gives directional stability and control. because of the solid construction the desired shape can be made exactly.

These boats can easily plane and can carry a larger HP outboard. The RIB bottom can take more abuse on a beach and can be pulled up a beach without fear of damaging the bottom, within reason.

The image shows the hull bottom of Walkers Bays Genesis RIB

Additional info


Engines; When choosing an outboard check the maximum recommended by the dinghy supplier and the manufacturers specs. The new 4 stroke outboards are larger and heavier than the old 2 strokes. Check dinghy manufacturers specs for Max engine size.

Maintenance; A well maintained inflatable will last for years, one left unattended in the sun will break down much quicker. Wipe down the tubes and use a spray on UV inhibitor regularly and you will increase life expectancy greatly. If you have a canvas or other type of cover this will help also. Other maintenance includes washing out the sand and dirt regularly.

RIBs have drain plugs and its best to drain and leave open when not in use. Remember however to put the drain plug back in.

Conclusion


Its impossible to cover all the options, but this is an attempt to set you off equipped with enough knowledge about Inflatables. You can spend more on a basic Inflatable like the Avon Redstart with the Hypalon material, than a RIB with cheaper materials.

The best approach is to prioritize the requirements and plan for the future.

More things to look out for;

  • Size and weight
  • Hypalon or PVC
  • Valise deflated size
  • Oars and oar storage
  • Rub strake
  • Fuel tank storage & tie down
  • Outboard storage
  • Grab handles or lifting lines
  • Lifting points if using davits
  • Drains for water and sand
  • Recessed inflation points

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