Same question for the safety sausages - I see them on DGX for $13, and then $25-$40 on other sites like DRIS or LeisurePro. Anything to look out for in terms of quality, materials, or are they all largely the same and should be chosen primarily on price?
Thanks for all the help guys!
I think it mainly depends on how visible you want to be, what options you want for inflating it, and whether you want to be able to inflate it at depth.
- A 6' tall tube that is 6" in diameter is going to be more visible than a 4' tall tube that is 4" in diameter. The DAN SMB has a radar reflective strip up the inside. There is some debate about how effective it really is, but I haven't see any actual evidence that it is useless. I don't know of any negative to having it.
- inflation options are: open bottom so you can inflate from your second stage regulator exhaust, valve that you can blow into, valve that you can blow into or push your low pressure inflator hose onto. Some SMBs are closed on the bottom, so you can only inflate orally or via LPI. Closed bottom (or closed cell) seem to me to be more likely to be used by a CCR diver. Or be one of the really cheap sausages that is just intended to be orally inflated on the surface.
- some have OPVs (over pressurization valves) and some don't. If an SMB does not have an OPV and you inflate it at depth and send it to the surface, it could rupture as the gas inside expands. The small, cheap sausages are generally intended to inflate on the surface and don't have an OPV.
Personally, if I were doing a drift dive in pretty calm conditions, I would be fine with a cheap, small sausage. But, if I were diving in choppy or rough conditions where the boat is moored, I would definitely want something I can deploy from depth and that is bigger and more visible from a distance.
On a drift dive, the boat is actively looking for you (and your safety sausage) and you are probably going to surface not too far from the boat. Especially if it's not rough, you should have no worries about the boat seeing you.
But, imagine that you're diving a 100' wreck off North Carolina. The boat is tied into the wreck (i.e. anchored). Surface conditions are a fairly common 4' swell. They are expecting you to come up the anchor line and surface next to the boat. They may or may not be doing a good job of watching for you to surface away from the boat. Now imagine that you get away from the wreck on the bottom. Maybe you got lost or maybe current took you away from it. You realize that you are going to have to make a free ascent. Thus, you need to deploy your SMB immediately, from depth (so you want it to have an OPV). The whole time you're thinking about it then doing it, the current is carrying you further away from the dive boat. Your SMB hits the surface while you are still making your ascent. You do a safe ascent, with a safety stop, so you've already been drifting in the current for 6 or more minutes. Hopefully, someone on the boat has seen your SMB and they are now tracking you. But, the boat can't unhook from the wreck to come get you until all the other divers have made their ascent and are safely back aboard. Depending on circumstances (like how early in the dive you got away from the wreck and started your ascent), that could take another 45 minutes. You can drift a long way in the current in that time.
Now, if you are in 4' seas and have a 4' sausage and you're half a mile from the boat, how easy do you think you will be for the boat to still see? Will you be wishing you had a 6' sausage that was a bit fatter?
I have been on a boat where almost this exact scenario happened. Except, when I saw it, the guy actually hit the surface pretty close to the boat, so the boat crew saw him right away. But, the current carried him past the tag line and he couldn't swim to it, so he got carried off while we watched him and waited for the rest of the divers to come up. By the time we unhooked and went after him, he (and his inflate safety sausage) was literally out of sight. We just had to head in the direction he went until we finally spotted him.
What you need depends on the diving you want to do. But, if you were to go with a good quality 6' SMB (open cell, with an OPV), I don't imagine that you would ever regret it and wish you'd gotten something smaller or less expensive. And you probably will also never end up wishing you'd gotten something bigger, either. OTOH, if you're only going to go to the Caribbean and do drift dives in calm seas and you want something smaller and lighter to take with you, one of the cheap sausages might be all you ever need.
