Immersion Suit – Different Types, Anti-Exposure Suits, And Thermal Protective Aids

Immersion Suit – Different Types, Anti-Exposure Suits, And Thermal Protective Aids - Merchant Navy Info - News

An immersion suit is a body-covering suit worn specifically for swimming and survival in emergencies at sea. Therefore, this suit is also known as a survival suit or rescue suit and is used in commercial operations. Today, immersion suits are a must-have on ships and oil rigs to protect against cold water, rough seas and dangerous situations. Therefore, all sailors, commercial fishermen and crew members of cargo ships wear immersion suits that provide visibility and prevent drowning.

Made of waterproof material, they also provide protection against hypothermia and protect the limbs. Some suits have straps that allow for ankle adjustments and a better fit. immersion suits are usually made from neoprene, any type of rubber that is completely waterproof and also can withstand extreme water and fire temperatures. The immersion suit adapts to the human body without exposing any part to water. It also has a protective hood that covers the head and protective gloves. Thus, it provides warmth to the body, and the inflatable pillows and air bubbles increase buoyancy.


  1. Everyone on board must wear a immersion suit. In addition, additional immersion suits should be provided for security personnel.
  2.  immersion suits may be insulated, non-insulated, or worn together with a life jacket (all must have sufficient buoyancy).
  3. Made from waterproof material.
  4. Clearly visible International RED. Note that most other LSA devices are bright orange.
  5.  immersion suits must be unpacked and donned within 2 minutes without any outside help or support.
  6. You must dive into the water from a height of at least 4.5 meters without injuring yourself or damaging your immersion suit.
  7. The suit should cover the whole body except the face. Hands should be covered unless tightly fitted gloves are available.

Types of Survival Suits 

There are three types of survival suits. The main types can be easily described as follows: 

The first type of survival suit is worn mostly by fishermen who fish in below-freezing temperatures. These fishermen wear their survival suits all the time so that their bodies do not lose heat and they stay warm and insulated all the time. The second type of rescue suit is one that is equipped for all ships, boats, and oil rigs. This is a mandatory requirement, and without it, workers cannot work on ships or oil rigs. The third and last type of immersion suit is known as an inflatable immersion suit. However, unlike the previous two immersion suits, this rescue suit does not completely cover the person’s body.

The inflated cover only covers the person’s hands and legs, thus keeping the person afloat and safe in the event of an emergency. Due to the compact shell, this suit is easier to wear and carry than the previous two suits. Some immersion suits are also equipped with an emergency flashlight, a whistle, and a lead that can be attached to the body of the person being rescued. This line, also known as a buddy line, is designed to ensure that everyone stays together and that no one gets lost in the water. Great advances have been made in the manufacturing and development technology of immersion suits. In the future, further advances will help make this application even more successful.

Cold Protection Suits 

See the Fire Safety Plan for the number and location of cold protection suits.

  1. Made of non-flammable, waterproof material.
  2. High visibility international color ORANGE.
  3. The suit must be able to be unpacked and donned in under two minutes without outside help or support.
  4. When donned, the wearer must be able to dive into the water from a height of at least 4.5 meters without injury to life or limb or damage to the suit.
  5. Covers the entire body except the head and hands.

The Suit Requires Gloves And A Hood 

  1. It is equipped with the pocket for a portable VHF radio 
  2. It has a side field of vision of 120 degrees.
  3. It must not continue to burn or melt after 2 seconds of being surrounded by fire.
  4. It must be possible to perform daily tasks while wearing it.
  5. The wearer must be able to ascend and descend a vertical ladder at least 5 meters long.
  6. The wearer must be able to swim at least 25 meters in water and access a lifeboat.
  7. The suit must not lose body heat at a rate of more than 1.5 degrees per hour for the first 30 minutes in water at 5 degrees Celsius.
  8. The wearer must be able to return from a prone position within 5 seconds, with or without a life jacket. 

Thermal Protection Aids 

Information on the number and location of TPAs ​​is given in the Fire and Safety Plan.

  1. Made of non-flammable and waterproof material 
  2. High visibility color International Orange 
  3. The thermal conductivity of TPAs ​​must be less than 7800 W/m^2.K 
  4. TPAs ​​must limit convection and evaporation of heat loss from the wearer’s body 
  5. TPAs ​​must function in temperatures between -30 and +20 degrees 
  6. Wearers must be able to remove the TPA in water within 2 minutes if it affects their ability to swim 
  7. Covers everything except the face 
  8. TPAs ​​must be easy to unpack and put on without being assisted in the survival boat or lifeboat.
  9. The third officer must ensure that this important equipment is regularly checked and functions as required in adverse circumstances.

Frequently Asked Questions

What Is The Function Of An Immersion suit?

Immersion suits cover the entire body and are worn by sailors, mariners, and commercial fishermen to stay afloat during emergencies at sea. Hence, they are also called survival suits or rescue suits.

How Long Can You Survive Wearing An Immersion suit?

According to SOLAS/LSA regulations, immersion suits must meet specified safety and performance requirements, such as wear time of no more than 2 minutes, impact protection of up to 4.5 meters, and hypothermia protection of 6 hours.

What Types Of Immersion Suits Are There?

There are two types of immersion suits: work suits, which are worn for long periods at sea, and survival suits, which are worn in emergencies.

How Often Does An Immersion Suit Require Maintenance?

 immersion suits are important safety equipment and should be well maintained. immersion suits older than ten years should be serviced annually at an authorized service station.

Do I Need A Life Jacket With My Immersion suit?

No, you do not need a life jacket with your immersion suit. Designed to be worn without a life jacket and equipped with a light and whistle, it complies with life jacket requirements.

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