If air collects in the legs as the subject enters the water headfirst, it should be expelled automatically.

All tested survival suits have zippers, and it is important that these are regularly checked for corrosion and waxed or lubricated (see “Fastening Details”). In several cases, corroded zippers have made it impossible for crew members on sinking ships to close their survival suits.

The best guarantee for a watertight wrist seal is to incorporate the glove, either a five-finger glove or a lobster claw glove, into the suit.

Rough seas have also been associated with increased body heat loss and decreased suit insulation. This is due in part to the increased activity required to maintain a stable body posture and airway freeboard in waves.

The present study shows that the total thermal resistance of the dry suit system decreased by 14% from the calm water condition to a wave height of 70 cm when tested on humans.

Breaking waves can wash over the victim's face and interfere with normal breathing. This has led to the development of spray hoods attached to the immersion suit to protect the victim from wave spray. The design of spary hoods is crucial for optimal performance... Rough sea conditions also cause increased suit leakage which reduces thermal insulation.

Special care must be taken when the lifejacket is of a “behind the neck” non-buoyancy design; this type of life jacket could cause a survivor to tilt head down in the water when used in combination with an immersion suit

Many immersion suit standards require thermal protection properties to be tested in calm, circulating water, while these suits are generally used in harsher environments where they often underperform. However, it can be costly and logistically challenging to test immersion suits under realistic conditions.

Practical Sailor technical editor Ralph Naranjo (5-foot-9, 190-pound) was unable to pull the Viking PS5002 sleeves over his forearms while wearing a fleece, and had to remove the fleece to don the suit, forgoing insulation. extra offered by the garment. Its size classification was for individuals up to 6 feet, 6 inches and 330 pounds.

Finally, Hall et al in 1954 (Reference 61) already noted that body insulation had little effect on hand cooling even when a maximum insulation of 4.7 Clo was used… the maximum body insulation, which is about 4 Clo per inch of fabric thickness, does not significantly prevent hands from getting cold

It is concluded that testing and certifying immersion suits with humans in calm waters will result in an overestimation of survival performance in harsher, but more realistic conditions, such as those found offshore that often include wind and waves, and the possibility of water ingress. , all of which will increase thermal stress. If this stress is not compensated for by the thermoregulatory system, deep body temperature will drop, leading to the potential development of fatal hypothermia that might not be anticipated. of tests conducted in calmer conditions

Death can occur from one of four stages of immersion: • Stage 1 Cold Shock (3 to 5 minutes) • Stage 2 Swimming Failure (3 to 30 minutes) • Stage 3: Hypothermia (after 30 minutes) • Stage 4: Post-rescue collapse (during or hours after rescue).

The examiners noted that the glue used to attach the main part

the zipper on the body of the suit had failed. Failure of the suit in this location will prevent the suit from achieving a watertight seal. Such conditions present a serious risk to crew members in a survival situation.

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The addition of wind and waves caused significant reductions (27 and 28%) in the in situ clo value compared to that observed in still water… When combined, the reduction in the in situ clo value due to the input of 500 ml water and wind and waves was -42%

Universal” was the size stamped on most of the suits we tested, and this “one size fits all” survival suit size range seemed overly optimistic and raised a few questions… Our female tester (5ft 6in and 130lbs) found the hood seal too loose on the Stearns 1590, which seemed designed for men with larger heads. He found that the loose seal allowed air to rush in and out as it bobbed on the surface. The effect caused heat loss and the opportunity for water to replace bled air if inundated by a breaking wave.

identifies that even under ideal conditions, the materials and adhesives used in the construction of immersion suits have a finite lifespan and will inevitably experience a reduction in strength or loss of water integrity over time

For those aiming to develop the integrated immersion suit system, it must be remembered that: (a) getting wet is potentially very dangerous (b) a dry system must be provided to achieve protection from all four stages of immersion (c) leakage as little as 1/2 liter of water in the system will reduce insulation by 30%  (d) The maximum insulation that can be added to a suit to prevent heat loss and still be worn is 4.5 Clo in air.

Clothing Insulation Measurement. The measure of isolation conceived by Gagge et al. in 1941 (Reference 47) is the Clo value. This can be measured using humans or an immersion thermal manikin.

The leaks were discovered in connection with a routine pressure test, which, according to the IMO recommendation, must be carried out for the first time within three years.

In general, there was still dissatisfaction with the suits and very familiar comments: • Flotation position was not satisfactory (too little freeboard) • Small people almost lost in the suit after a five meter jump into the water • Leak in the glove seal with suit • One-size-fits-all suit does not fit everyone • All zippers need regular maintenance • Very difficult to swim in suit • Leaks in suit, which in some cases caused great difficulty getting on the liferaft • Little durability of the fabric • Good maintenance requirement.