Lift Bag


A lift bag is an essential piece of scuba diving equipment used to assist divers in raising heavy or unwieldy objects from the depths of the ocean to the surface. These air-tight bags employ the principles of buoyancy and displacement to provide a safe and efficient method for lifting various items, including sunken treasures, marine debris, and underwater research equipment. In this entry, we will explore the components, types, uses, and safety precautions associated with lift bags.

Components of a Lift Bag:

A lift bag is comprised of several key components that ensure its proper function and durability. These components include:

  1. Air-tight Material: Lift bags are typically constructed from heavy-duty, puncture-resistant materials such as nylon or PVC-coated fabric. This ensures that the bag remains air-tight and maintains its structural integrity throughout the lifting process.
  2. Inflation Mechanism: An essential part of a lift bag is its inflation mechanism, which can either be an oral inflator or a low-pressure inflator (LPI) compatible with a diver’s buoyancy control device (BCD) hose. This mechanism enables the diver to fill the bag with air, increasing its buoyancy and lifting capacity.
  3. Straps and Attachments: Lift bags are equipped with durable straps and attachment points to secure the object being lifted. These straps are typically adjustable to accommodate different sizes and shapes of objects.
  4. Dump Valve: A critical safety feature of a lift bag is its dump valve or overpressure valve, which allows excess air to escape from the bag if it becomes overinflated. This prevents the bag from rupturing due to excessive pressure and ensures controlled ascent rates.

Types of Lift Bags:

There are several types of lift bags available, each designed to meet specific requirements and uses:

  1. Open-Bottom Lift Bags: These bags feature an open bottom, which allows for rapid inflation by simply allowing air to displace water inside the bag. Open-bottom lift bags are suitable for lighter loads and shallow depths.
  2. Closed-Bottom Lift Bags: Closed-bottom lift bags have a sealed bottom and require an inflation mechanism to fill with air. These bags are generally more versatile and capable of lifting heavier loads at greater depths.
  3. Parachute Lift Bags: Parachute lift bags are designed with a unique shape that resembles a parachute canopy. This design maximizes stability during ascent and reduces the likelihood of the bag tipping over or becoming entangled.

Uses of Lift Bags:

Lift bags serve various purposes in the scuba diving and underwater exploration community, such as:

  1. Salvage Operations: Lift bags are frequently used to retrieve sunken objects, including boats, vehicles, and other valuable items, in salvage operations.
  2. Marine Debris Removal: Environmental and conservation efforts often employ lift bags to remove large pieces of marine debris, such as abandoned fishing nets or plastic waste, from the ocean floor.
  3. Underwater Research: Scientists and researchers utilize lift bags to transport delicate or heavy equipment to and from underwater research sites.
  4. Underwater Construction: Lift bags are employed in underwater construction projects, such as installing or maintaining underwater pipelines and cables, to maneuver heavy materials and equipment.

Safety Precautions:

Using lift bags requires proper training and adherence to safety precautions to ensure a successful and accident-free experience:

  1. Lift Capacity: It is crucial to choose a lift bag with the appropriate lifting capacity for the object being raised. Overloading a lift bag can result in equipment failure and potentially dangerous situations.
  2. Ascent Rate: Maintaining a controlled ascent rate is essential to prevent rapid expansion of the air inside the bag, which could lead to ruptures or uncontrolled ascents.
  3. Entanglement: Divers should be vigilant about potential entanglements with the
  4. lift bag, straps, and attachment points. Clear communication with dive buddies and proper positioning can help minimize the risk of entanglement.
  1. Decompression: When using a lift bag at significant depths, divers must consider their decompression obligations and plan their ascent accordingly to avoid decompression sickness.
  2. Surface Traffic: When conducting lifting operations near the surface, divers must be aware of potential boat traffic to prevent collisions and injuries.
  3. Training: Proper training and certification in using lift bags are crucial for ensuring safe and efficient operations. Many diving organizations offer specialized courses in lift bag usage and techniques.


Lift bags are invaluable tools in the world of scuba diving and underwater exploration, providing divers with the ability to safely and efficiently raise objects from the depths of the ocean. Understanding the different types of lift bags, their uses, and safety precautions ensures that divers can make the most of this essential piece of equipment. Proper training and adherence to safety guidelines will help divers successfully navigate the challenges of underwater lifting operations and contribute to the ongoing exploration, conservation, and understanding of our underwater world.