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There is an awful amount of knowledge you need to know to safely launch and recover diving boats, read on to learn more....
Types of Boats
There are three main types of boats that divers use:
- The inflatable
- The Rigid Inflatable Boat or RIB
- Hard Boats
The Inflatable
The inflatable usually has a flexible hull. It is light and easy to carry.
They are stable in the water but their steering can be affected by the wind. They are poor in moderate seas and better used for inshore diving
- Slower / limited engine size
- Poor in moderate seas
- Smaller (no twin sets?)
- Hard to mount instruments
- Tiller steering
- Light (easy to tow)
- Can be carried over the beach
- Cheaper to buy (half the price of a RIB)
The Rib
The RIB was invented by the Royal National Lifeboat Institution (RNLI) and the US Coastguard, in an attempt to produce a fast versatile rescue craft, for use in shallow waters, which larger offshore craft could not navigate. The result was a Standard Mono hull with an inflatable collar instead of solid sidewalls. This was a revolutionary design that was set to start a new wave of leisure boats i.e., the RIB.
The RIB has a glass fibre or aluminium hull with massive buoyancy. It is generally larger with because it has a deep V hull it can and cut through the water and be much faster. It can handle heavy seas but is a little more difficult to steer at low speeds. Its characteristics include:
- Faster
- More comfortable for divers
- Can take larger engines
- Good in moderate seas
- Larger and can carry more divers
- Better instrumentation
- Remote steering
- Heavy and more difficult to tow
- Harder to launch
- Can be expensive
Anatomy of a boat
Starboard comes from the word 'Steer board'. This is the rudder type affair that used to be on the right-hand-side of the vessel and not the stern.
 Port comes from the use of the Steer board as the vessel always had to berth on the left-hand-side or they'd smash the steer board on the right. Hence the Port side was the left side.
The beam is the width of the boat and the draft is the depth of water needed to float the boat.
Amidships refers to the middle of the boat and aft refers to the rear.
The Sponsons
The tubes or sponsons are made from very strong synthetic materials, In modern Ribs there are three components to this:
- An inner, air sealing layer.
- A middle layer of reinforcing material which give high strength and stretch. this is usually Polyester, Nylon or Kevlar. Kevlar is the better but more expensive.
- An outer abrasive resistant skin. This must be resistant to things like battery acid, petrol and oil and of course abrasive diving equipment particularly cylinders. Ultra Violet light can also have an effect on most rubber based materials. Neoprene and Hypalon have good resistance to this.
The sponsons are divided into 3 or 4 separate air tight compartments, each will have its own inflator valve. This will ensure that should one chamber be punctured the RIB will still float. These compartments are separated by flexible air tight "baffles" which also help to equalise the pressures in each chamber. Normally these baffles are about amidships on either side.
An internal Baffle
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