Types of SMB/Safety Sausage

[2airishuman]

Just a quick question is there a preferred color for an SMB (or safety sausage... not sure if there is a difference)?

All-yellow SMBs, as noted upthread, are used to notify surface support of the need for assistance with an underwater emergency.

Two-color SMBs with an orange side and a yellow side are intended to provide better visibility than either color alone, since the most readily visible color can vary depending on conditions. Orange SMBs are the most common.

Also is there a preferred type? As far as I can tell there are two types the ones you would inflate through a big opening by purging your regulator into and the other being the orally inflated type. Is there pros and cons to either?

Usually differences in size and inflation method go hand in hand.

Smaller SMBs, typically 2-3 feet long, are intended to be inflated at the surface and held in the hand. I have one that I keep attached to a whistle and mirror, and bring it on boat dives. These smaller SMBs are best understood as a device used in calmer seas to communicate with a dive boat that is nearby and actively looking for you. Usually these small SMBs are meant to be orally inflated, and have a valve that will keep them inflated. That works out fine if everything is happening on the surface.

Larger SMBs, often called DSMBs (delayed surface marker beacon), are usually set up for more than one method of inflation. The five common ways they can commonly be deployed are: 1) from a supply of bubbles, either from regulator exhaust, BC exhaust, or depressing the purge button on a regulator; 2) using the BC autoinflator hose; 3) orally through a tube; 4) from a very small air cylnder ("crack bottle") attached to the SMB; or 5) from a CO2 cartridge. Most larger SMBs for SCUBA diving can be inflated from a stream of bubbles with many also having a tube that can be used either for oral inflation at the surface or inflation from a BC hose. The ones with CO2 cartridges mainly appeal to freedivers since they do not have a supply of air. The "crack bottle" style have never caught on in the U.S., but are apparently popular in the U.K., where I understand it is more common to deploy an SMB routinely at the end of every dive.

There is some overlap in design and usage between larger SMBs and lift bags.

Larger SMBs serve a number of purposes. They can be used for signalling when separated from the dive boat. They can be deployed underwater to notify surface support of the location and imminent surfacing of divers. Underwater deployment also can warn craft not involved in the dive operation of the presence of divers. They can be used as an emergency source of buoyancy. For technical dives, they can be used to aid in maintaining a specific depth for staged decompression.

Large SMBs require practice and skill to use particularly if deployed underwater.

I carry a 6' SMB on certain dives.

 

[Jim Lapenta]

DSMB's come in small and large sizes. An SMB is ok if that's all you can get your hands on.
I carry two usually. A 3 ft DSMB for shooting from depth since it takes much less air to inflate and is much easier to manage than a 6 ft length of material. It also has less lift and poses less danger of dragging the diver to the surface should they become entangled in the line.
The larger one is about 6 ft and that's the one I use at the surface though it can be deployed from depth. Deploying a big one from depth requires practice, patience, and a lot of attention since they can have upwards of 50 lbs of lift or more. Get tangled in the line and you could be in big trouble.
Small smb's are ok for surface signaling IF the water is flat. Get in 3-4 ft swells with a little distance between you and the boat and they are kinda useless. They provide an upline. That's the primary purpose of them. On the surface you want to get the big one up and inflated for maximum visibility.

 

[cool_hardware52]

Small smb's are ok for surface signaling IF the water is flat. Get in 3-4 ft swells with a little distance between you and the boat and they are kinda useless. They provide an upline. That's the primary purpose of them. On the surface you want to get the big one up and inflated for maximum visibility.

A 1 meter bag that reaches the surface full, and stands up without requiring 1/3 of it be pulled under water is more effective than a big bag that arrives at the surface 1/2 full and is difficult to keep up right. Big bags often need 10-20 lbs of downforce to keep them up, and even more it is windy.

Often I hear the claim that a giant bag is the answer when the surface conditions are less than ideal. Of course swells are commonly accompanied by wind, and big bags in the wind end up blown over, and or towing the diver.

No one good answer, but my choice remains a low volume 1 meter bag designed to remain upright to mark a drifting deco team, and maybe larger oral inflate safety sausage if the conditions merit it.

I want two per team in the event one is lost or fouled and has to be cut away.

Bigger is not always better.

Tobin