Dirkadiver:
I'm trying to decide which to buy for tech diving. At my local dive shop, I couldn't find any SMB's that rated lift capacity. Are SMB's & signal sausages the same? I'm trying to decide on what to buy. The 100# lift bags seem so big. Is there something comparable out there in a smaller package?
Hi Dirk. There have been some good answers to your questions. I thought I would offer a couple of additional points. In diving, we have allowed the terms "lift bag", "smb", "safety sausage" to take on a variety of meanings. What is really important is two basic distinctions.........there are devices designed for lifting loads and there are devices designed for enhancing surface visibility while providing a reference for safety/decompression stops.
True Lift Bags. Lift bags are designed for lifting a load from the ocean bottom. They are typically made from much heavier nylon (or other) fabric and have a lifting harness capable of handling the load appropriate to the bags displacement. A 50 pound lift bag requires a minimumly built lifting harness while a 500 pound lift bag requires a more robust strap or harness. They also have air release valves appropriately positioned to allow a diver to alter the contents and manage the speed of the load as it moves upward in the water column.
Personal Markers. This is the category of devices most of us talk about here. Seldom are divers buying a bag to lift a load. Instead, they simply want to mark their position in the water to make themselves visible on the surface. These devices come sometimes shaped like a traditional lift bag and others come shaped like a "sausage". Both are actually designed for the same purpose.......to allow the diver to be visible on the surface. The less expensive "safety sausages" are typically only inflated orally and are only inflated at the surface. They perform the function of making the diver more visible on the surface, but cannot be used as a reference for doing safety/decompression stops. Their "surface-only" inflation method also eliminate their use for another important safety function......they cannot be sent to the surface in ADVANCE of the diver. The more expensive personal marker bags and personal marker buoys provide a means of inflation BEFORE the diver reaches the surface. This allows the previously mentioned reference for stops and (more important) provides surface searchers (boat crew, other travelling boats, search and rescue personnel) with position information about the diver PRIOR to the diver reaching the surface.
Personal Marker Shape. As I said previously, personal markers come in the traditional "lift bag" shape and the sausage shape. While choosing which shape to use is basically a personal preference, there is a slight difference. The SMB (sausage shaped bags) do provide a bit more distance visibility for a surface watcher to spot a diver. The reason is common sense......a taller object might be easier to spot from a distance than a more low-profile bag shape. The important thing to mention is that even the personal marker bags that are shaped like traditional lift bags MAY not be ideal for lifting loads. Often, they are made from fabric that is thinner and have a strap system that MIGHT NOT be suitable for a load that equals the bags displacement.
You can follow this link for an example of a personal marker bag.
XS Scuba Personal Marker Bag
You can follow this link for an example of a surface marker buoy (SMB)
XS Scuba Surface Marker Buoy (SMB)
I hope this helps you.
Phil Ellis
) burst the sausage before it made it to the surface. It was quite funny except for nearly making one of the divers hanging deaf from the resulting explosion.
