Surface Marker Buoy (SMB) : Ideal length

[chrpai]

SMBs should never be used instead of a dive flag. Ever. However, if you lose the flagman or get blown off of the reef or wreck (like here in the Keys), they are far, far better than nothing.

The only time I ever see (towed) dive flags in Lake Travis is in O/W classes inside of the dive park that typically has no boat traffic. After that, nope, never.

BTW, I think it was misunderstood what I use an SMB for and what other procedures I follow... I don't want to have a haircut so trust me... I'm doing fine.

 

[lindenbruce]

I don't know how you guys can shoot a 6ft smb, properly fill, at safetly stop or even deep stop kind of depth while maintaining buoyancy. Think about it, to maintain buoyancy, you can put one breath into the SMB. Deploy at 15ft (safety stop) or even 50ft (deep stop), this SMB will be a limpy one at surface.

Actually it's not that hard at all. The deeper you are the better for a good fill due to decreased pressure as the bag ascends and the air expands. By the time you are blowing your bag you are most likely at your first deco stop anyway, not a 15 foot safety stop. So you are already breathing off your deco rig and your long hose is clipped off. Get neutral and use your second stage reg to fill the bag. Insert the mouth piece into the bag opening, if it's of that type, and give a good one to two second blast from the purge button. As soon as you feel the bag making you positive you release the bag and let it shoot up on your reel. It will fill plenty by the time it reaches the surface.

If you are blowing your bag at 15' then yes you are going to need to put more into it so it inflates properly on the surface. But then, why are you waiting until you reach 15' to deploy your bag anyway? Deploy it sooner and reel in the line as you make you slow ascent to 15'. That way it gives the boat crew advanced warning of where you are.

If yours is the oral inflate style the application stays the same. Get neutral first. Then once you have everything in hand take a good breath from your reg and blow into the oral inflate. If the bag has not yet made you positive take another hit from your reg and repeat. But you are most likely there by that time. Again, release and let her shoot up on your reel.

As always, make sure you are ready before you inflate. The line lock on your reel is backed off to allow the reel to deploy line. Then hang on for the ride baby!!!!! Bruce

 

[The Chairman]

The only time I ever see (towed) dive flags in Lake Travis is in O/W classes inside of the dive park that typically has no boat traffic.

That is probably fine in Texas, but I really don't know. In Florida, the law states that you must be within 100 ft of the flag and the boats can't be under power within 300 of the flag (steerage only). FWC does not have an allowance for using an SMB in lieu of a dive flag, but I have never heard of a ticket being issued for using one when the situation merits it.

 

[Dive-aholic]

Exhalation is one method but not using just 1 breath. You deploy by opening it to the 2nd stage vent but I usually do 3-4 big, sharp breaths. The more preferred way is to use another regulator like a safe second or a stage cylinder. If the DSMB is "limpy" then it is a reflection of poor technique. One must maintain constant tension on the line so that it props itself up. If not, then yes it will be less effective as a surface marker.

That is not the more preferred way in all environments. While that is my preferred method I am usually diving in water warmer than 60F. Try that in water below 50F and you are risking a free flow that you will not be able to get control of again.

 

[Steve_C]

I have some smaller SMBs in a drawer that I bought some time ago. As noted get one at least 6 feet. Get one that can be inflated at depth by the reg. Get one that you will carry with you.

I did two drift dives out of Jupiter, FL. On both we had limited viz for that area. (30-40 ft) My instabuddy had a big camera. We were the last two to splash. We never saw the DM who went first. We never saw a flag that was being towed although we were told such existed.

I want my SMB up there as soon as I start my ascent and throughout the safety stop. Its purpose is strictly to help the boat to find me. That's true off Florida or off NC.

 

[idive2]

I have both a 3 ft and 4.5 ft halcyon closed circuit smbs. I have used the open bottom smbs and
didn't like messing with the loose octo after smb was deployed. My 4.5 ft which is also wider than
the 3 ft takes 6 full breathes at the surface to inflate. 2 full breathes minimum at 50 ft to fill
30 percent takes a while and buoyancy becomes an issue. I can inflate my 3 ft with one full breath.
While I prefer the greater surface area on the 4.5 ft marker the 3 ft deploys much quicker and causes
fewer buoyancy issues. I may try the 4.5 again but getting spoiled with the ease of inflating and deploying
the 3 ft smb. Even the 3 ft Halcyon is available with a pressure relief valve if deploying from depth. A bit
more pricey than the more standard 3 footers but a pretty nice smb.

 

[tracydr]

The only time I ever see (towed) dive flags in Lake Travis is in O/W classes inside of the dive park that typically has no boat traffic. After that, nope, never.

BTW, I think it was misunderstood what I use an SMB for and what other procedures I follow... I don't want to have a haircut so trust me... I'm doing fine.

We always dive with a dive flag at Lake Pleasant, class or not. Why do you guys not use one? There are boating regulations regarding dive flags in AZ. I wonder if there are any in TX? I assume there aren't any regarding SMBs, though since an SMB instant a real dive flag with the proper markings.

 

[Griffo]

I've got a 6ft Buddy SMB and it takes a real lot of air to fill it as it's also quite wide. I had the chance to use a Halcyon 4.5ft and learned how easy it is to blow from pretty much any depth. The 4.5ft is now my standard "go to" SMB with the 6ft reserved for times when I expect there to be a big swell.

 

[Abdullah]

SMBs should never be used instead of a dive flag. Ever. However, if you lose the flagman or get blown off of the reef or wreck (like here in the Keys), they are far, far better than nothing.

Excellent advice in your area. Not so excellent in mine - people here aren't tuned to the meaning of a dive flag and it's not much of a presence. Four or more feet of blaze orange standing in the water does get their attention, and most won't intentionally run over the buoy for fear of what might be below it.

 

[DCBC]

I am ready to buy a SMB and see models between 3 and 10 ft long!! What is most reasonable including for high sea? 4 ft? 6ft?

Any recommendation on the brand (must be able to inflate with regulator; better with valve so air does no go out if not straight on the surface.

Personally, I like Carter SMB's. The length of the bag depends upon the sea state that you are diving in. As I usually dive offshore wrecks, I use a 10 foot SMB (which uses less than 1 cu. ft. to fill).

I've used this bag in heavy weather and it can still be easily identified. Carter's expertise is in lift bags used in the commercial diving industry. Quality and durability are excellent. They also make longer and shorter models.