Weight to Keep SMBs Uptight?

[Akimbo]

Has anyone experimented to determine how much weight is required to keep a 4'/1.2M, 5'/1.5M, or 6'/1.8M SMB upright without a diver hanging on to it?

 

[johndiver999]

There is no definitive answer. It depends on sea state. In my experience the actual weight requirements are considerable, so much so that it is impractical. If it is rough, you need a big smb, but it takes a lot of tension to keep it close to vertical. An smb with a lot of integrated weight is a problem because it makes the diver overweighted, and if the diver caries more than one weighted smb the problem is magnified.

 

[decompression]

I’d be comfortable saying 1 to 1.5 lbs.

 

[Johnoly]

Has anyone experimented to determine how much weight is required to keep a 4'/1.2M, 5'/1.5M, or 6'/1.8M SMB upright without a diver hanging on to it?

Since we hunt, the additional weight comes from either the tools we hunt with or the weight of the catch we accumulate as we dive. Those weights are usually attached to the smb line in different ways at the safety stop and then help add weight to make the smb stand up as well as free our hands from holding things to do other tasks. Sometimes that extra weight can reduce the height of the smb and make it sink some(or too much reducing smb viz). In most cases we contribute 5-10 lbs of underwater weight (topside is much different) to hang on the line. We use Carter 8 inch diameter smb's that are custom made at 5ft with special releases and no velcro for how we dive. The wraps, OPV valves and inlets are easily replaceable if they wear. I have about 800 dives on my current smb with no holes and replaced the wrap twice and the inlet once, the OPV's are bullet proof. The 2 color SMB's are wide enough to be seen easily 1.5 miles away which is usually our max drift in 60 minutes.
I guess it just depends on how you dive as to what smb you use, so everything is different for the type of dives you do. In our case, diameter is more important than height for smb viz to us captains.

 

[steinbil]

Sorry to revive an old thread, but I had this same exact question, and wondered if anyone has experimented with this? Any testing done? @Akimbo: did you ever figure this out?

 

[Akimbo]

Any testing done? @Akimbo: did you ever figure this out?

I haven't got around do it. Wind would also be an important variable.

 

[whynot]

FWIW, I stuck a 3lbs solid lead weight to one of these once: Halcyon Dive Systems. The weight was hanging midwater and the bag stayed upright on the surface - 2lbs would have prob been just as effective.