On ships that are required to provide every person on board with an immersion suit complying with the requirements of the Life – Saving Appliances
Immersion Suits may be either stored at clearly identifiable locations close to the survival craft embarkation stations or may also be distributed to each individual member of the crew.
- at least two additional immersion suits of the same type located in the navigating bridge
– at least two additional immersion suits of the same type located in the engine room
– at least two additional immersion suits of the same type located at workstations where the crew performs its normal duties (except watch -keeping duties); if the horizontal distance from the workstations to the stowage position of the immersion suits is more than 100 metres.
– an adequate number of immersion suits intended solely for training purposes and marked accordingly. In the case of ships equipped with vacuum packed immersion suits an adequate number of non – vacuum packed immersion suits intended for training purpose are to be provided and these shall be marked accordingly
Air pressure testing of immersion suits and anti-exposure suits is to be carried out in accordance with the manufacturer’s recommendations and the guidance contained in as applicable, at intervals not exceeding three years.
Testing should be performed at a suitable shore – based facility or alternatively on board the ship provided that suitable testing equipment is available. Any repairs to immersion suits or anti -
exposure suits should be carried out by a facility having trained personnel and access to the manufacturer’s instructions, parts and adhesives.
Wet suits are for people who immerse themselves in cold water under various different circumstances. Designed initially for scuba divers and then popularized by surfers, the wet suit has evolved from a simple layer of protection from the wet and cold into a “system” that warms, protects and aids the swimmer, surfer or deep sea diver that uses them.
Heat moves from a warmer object to the colder object. This is one of the basic laws of physics and you can argue about it until the cows come home and it simply will not change. Knowing is no suit that can prevent the exchange, but the transfer of heat from your body to the water around you can be slowed long enough to allow a diver to enjoy a deep dive for a much longer time by using a wet suit.
The amount of time it would take for a diver to suffer a serious loss of heat depends on his size, the temperature of the surrounding water, the diver’s physical exertion and the insulation material in his wet suit. A good, state-of-the-art wet suit is composed of three layers — a wicking layer, an insulation layer and the outer protective layer.
The purpose of the wicking layer is to keep the diver’s skin dry. Wet skin loses heat at a much faster rate than dry skin, so the wicking layer removes moisture from the skin and transports it to the next level of material, slowing down the loss of heat from the diver’s body. The insulation level slows down the heat loss considerably. There is no single, universal insulation that works for all divers under all conditions. In fact, a diver who spends a lot of time underwater in different locations and under different conditions will have a selection of wet suits to accommodate his variety of choices. There are four basic types of insulation packages – the wooly bear (any fuzzy wool-type insulator), open-cell foam (excellent when dry, but stiff), type-B marine thinsulate (considered the best) and radiant barriers (great in space, need to be combined with one or more of the other types to be effective in water). The outer protective layer’s sole purpose is to keep the inner layers dry. Polymers — rubber and plastic conglomerates — are often used by wet suit manufacturers for this purpose.
It is important to consider that the naked human body was not designed to live in much of the world’s ambient air temperatures. It can survive in almost none of the world’s water temperatures. To make up for this poor design feature, humans devised clothing as insulation that gives the margin needed for survival. The human body will become hypothermic in any water temperature under 91° F (body at rest) and any air temperature under 80° F (body at rest).
- How long can a person survive in cold water?
It depends. Factors such as water temperature, body fat, clothing, activity level, will to survive, etc., can significantly influence survival time in the water. You can survive longer in cold water if wearing a PFD and using heat retention techniques like the H.E.L.P. (Heat Escape Lessening Position) and Huddle position.
- What kind of clothing is best for preventing hypothermia?
Half of our body can be lost through our head; a warm hat is an effective hypothermia preventer. Clothing insulates by trapping air close to the body. Layering traps more air than single garments. Since water is an efficient heat conductor, fabrics that keeps you dry or insulate when wet are the best all around for people exposed to wet and cold environments.
- What is the best kind of personal flotation device (PFD)?
You cannot exactly tell it is the best, there is no one best PFD. Some PFDs have more flotation than others; some protect the body’s high heat loss areas; some are comfortable to wear while working; some have inherent flotation; some are inflatable; some are USCG approved and some are not. There are a variety of types and styles available for a range of situations and users. Make sure your PFD fits you and meets your needs.
- What kind of immersion suit should I buy?
Immersion suit manufacturers make suits with a variety of features and in sizes ranging from toddler to jumbo adult. You have a range to pick from. As with PFDs, there isn’t one right answer.