Lift Bags - Marking Tubes
The Surface Marking Tube (SMT) is also known as Surface Marker Buoy (SMB) or Delayed SMB (DSMB)
For an overview of all features and specifications see the table details in our TekTip below.
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DGX Safety Sausage$20.00 -
DGX All-Mesh Lift Bag Sleeve$10.00
WARNING
Some of the lift bags and surface marking tubes include a non-locking inflation connection fitting that supports easy and rapid power-inflation at the surface using the standard quick-disconnect low-pressure BC inflator hose. However, there are some safety concerns using that mode for deployment while at depth. Disconnecting the inflator hose from your BC at depth could compromise your buoyancy control in an emergency. Although the inflation connector on the device is non-locking, there is a possibility connectors could jam and fail to easily separate if the connectors are not clean and well maintained. As with any such device, it is also possible to create enough lift such that it could begin to drag you to the surface if there is any delay in release and the rapid power-inflation feature can reduce the time available before release.
For deployment at depth we suggest using an alternate low-pressure quick-disconnect inflator hose mounted on a stage or bailout bottle, rather than the primary BC inflator hose, for power inflation of this device. If this is your first experience with power-inflation lift bag or marking tube deployment at depth, first practice this type of deployment under controlled conditions.
How to Choose Between Lift Bags and Marking Tubes
Divers are sometimes confused about the difference between lift bags and surface marking tubes (SMT). Surface marking tubes may also be referred to as Delayed Surface Marking Buoys (DMSB) by technical divers.
Our factual but easy-to-read article helps you choose the appropriate bag by giving you information on:
- Why is one better at carrying a load to the surface
- Why is one a better surface marker
- Which has a dump valve that can be regulated on ascent
- Which has an over pressure relief valve (OPV) that cannot be regulated on ascent
For more information read Lift Bags versus Marking Tubes.
Lift Bags and Surface Marking Tube Features
| Device | Size Lift/Height |
Type Open/Closed |
Power Inflate Connector |
Color | Additional Features |
| DGX Gears Lift Bag | {65 lb | 30 kg | Semi Closed | No | Orange | D-rings Top & Bottom |
| Dive Rite Lift Bag | {75 lb | 34 kg} | Open | No | Orange | Top Handle, Reflective Tape, Built-in Sleeve, D-rings |
| Mares XR Lift Bag | {80 lb | 36 kg} | Closed | Yes | Orange | D-rings Top & Bottom, Sewn-in Bungee Loop |
| DGX Gears Lift Bag | {120 lb | 55 kg} | Semi Closed | No | Orange | D-rings Top & Bottom |
| DGX Safety Sausage | {44 in | 112 cm} | Closed | Oral Only | Orange or Yellow | SURFACE DEPLOY ONLY, NO OPV |
| Mares XR Small SMT | {39 in | 100 cm} | Closed | Yes | Orange | Compact, Sewn-In Bungee loop |
| Dive Alert Small SMT | {46 in | 117 cm} | Closed | Yes | Orange | Built-In Pocket, Reflective Tape |
| DGX Gears SMT | {4 ft | 1.2 m} | Semi Closed | Yes | Orange or Yellow | D-rings Top & Bottom, SOLAS Tape, Sewn-In Bungee loop |
| Apeks SMT | {4 .6 ft | 1.4 m} | Closed | Oral Only | Orange or Yellow | SOLAS Tape, Sewn-In Bungee loop, Stores in Apeks Ascend Reels |
| AP Diving SMT | {4 .6 ft | 1.4 m} | Hybrid | Mini-Cylinder | Orange, Yellow, Dual | Sewn-In Velco Strap, Top Grommet |
| Mares XR SMT | { 4.6 ft | 1.4 m } | Closed | Yes | Orange or Yellow | SOLAS Tape, Clear Pouch |
| DGX Gears SMT | {5 ft | 1.5 m} | Semi Closed | Yes | Dual Color | D-rings Top & Bottom, SOLAS Tape, Sewn-In Bungee loop |
| Dive Rite SMT | {5 ft | 1.5 m} | Hybrid | Yes | Orange | Built-in Sleeve, Reflective Tape, Wide {8 in | 20.3 cm} |
| Dive Alert SMT | {5.4 ft | 1.7 m} | Semi-Closed | No | Orange | Reflective Tape |
| Dive Alert Deluxe SMT | {5.4 ft | 1.7 m} | Hybrid | Yes | Dual Color | Built-in Pocket, Reflective Tape |
| DGX Gears SMT | {6 ft | 1.8 m} | Semi Closed | Yes | Orange or Yellow | D-rings Top & Bottom, SOLAS Tape, Sewn-In Bungee loop |
| Highland Giant SMT | {10 ft | 3.1 m} | Hybrid | Yes | Orange | HUGE {22 in | 56 cm} Circumference, SOLAS tape |
- Open = The bottom of the bag or tube is completely open and unrestricted. To fill with gas hold the opening over a second stage regulator or BC oral/power inflator, or hold the mouthpiece inside the opening, and operate the device to release gas out the mouthpiece into the bag or tube.
- Semi-Closed = The bottom of the bag or tube is open and inflates the same way, although more slowly, plus incorporates an funnel-shaped internal restriction (aka "duck-bill") that limits gas from escaping once it enters.
- Closed = The bag or tube is completely sealed and uses a one-way valve nipple for oral inflation. The average diver will require three or four breaths to orally inflate a {5 ft | 1.5 m} tube. Most inflation nipples also have a non-locking fitting that supports easy and rapid power-inflation by pushing on (and holding in place) a standard quick-disconnect low-pressure BC inflator hose.
- Hybrid = The bag or tube is both semi-closed and also includes an inflation nipple. Hybrid designs support the choice of any of the three methods of inflation: from the bottom opening, oral inflation, and power-inflation with a BC low-pressure hose.
