Surface Marker Buoy (SMB) : Ideal length

[jgl51]

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.

 

[Abdullah]

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.

6 feet is a practical length. Much longer and they become bulky in storage. The shorter ones don't have as much vertical reach on the surface. There are a bunch of brands. To be honest, the el cheapo I picked up at a mall works just as well as the more expensive name brands.

 

[DivemasterDennis]

6 feet minimum, 8 feet is plenty. Whether deploying at depth or at the surface, the point is that it be seen.
DivemasterDennis

 

[tanksforthememories]

I agree with Abdullah. Also remember too big and they are hard to inflate properly at shallower depths, you become too positively buoyant and may deploy prior to an adequate amount of fill. Without enough air it fails to properly stand vertically at the surface, which makes it less visible. If you are deploying from depth perhaps 6ft is a good length. If you are filling at the surface bigger is better just watch for boat traffic on your accent. Good luck.

 

[eelnoraa]

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.

 

[The Chairman]

I look for at least six feet in length, an OPV (Over Pressurization Valve), and an inlet that will allow me to use the LP hose off of my BCD. I simply don't have an issue with maintaining buoyancy and deploying this from depth. Neither do my students as this is part of my AOW class. Here's a great one:

http://www.diverightinscuba.com/catalog/liftbagssmb-drisdivegear-6ftsmbwwhistle-p-2914.html

 

[chrpai]

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.

Practice

One of our favorite dive sites on Lake Travis is a place called Starnes Island. It gets a lot of "party barges" full of people drinking lots of adult beverages, occassionally flashing value assets and frequently dropping goodies into the depths below. There is a lot of boat traffic and there's no way I'm surfacing without shooting a bag. Unfortunatly it sometimes attracts the idiots (usually on jet skis ) but at least you have a chance.

My 6' SMB has a duck bill bottom and I blow it by turning my head sideways and breathing out my reg's exhaust. I'm able to get a fairly good deployment from even 15'-20'. Robert certainly has no problems finding me to pick me up. (It's a 'drift' dive sometimes.)

 

[danvolker]

Personally, I think alot of boaters that are on the reefs we dive on, will never see the SMB, and even if they did, they will not "process" this...So they will always be running nearby smb's or floats of divers---Unless, there is a Dive Charter Boat policing your dive area, and warding off any approaching boats--even playing chicken if need be.

I would not consider sending up an SMB with the purpose of protecting me from an oncoming boat.....I do that by stopping at 10 feet...and listening.....and listening, and when I think the coast is clear, I do a rapid ascent from ten feet while being negatively buoyant( swim up ) ---and doing a 360 spin as I go, and on surface an immediate 360 scan. If there is nothing, I will wave up Sandra and Bill or who ever else I am with....If a boat is approaching and is not looking or seeing me, I am back down to ten feet in a few heart beats.

Normally we tow a torpedo float with a flag...but even with this( far superior to an SMB) I do the rapid spin the last 10 feet if the dive boat is not likely to be nearby--and if I have been hearing lots of boat traffic.

I would use an smb IF I was doing a deep wreck without a torpedo, and I wanted to do some deco after leaving it.....so the boat I was diving from would know where to look for us--that is the real function of an smb...Not for protection from stupid boaters....

An inflatable Kayak or hard shell kayak can be towed, and most ignorant boaters will see the kayak, and be afraid to run over the kayak due to the damage they would mentally process as likely if they ran over the kayak--$1000 or more in props, etc. The dive flag on the kayak they will probably miss, unless they slow down off plane when they approach the kayak.

If you have ever captained a 30 to 50 foot boat, and been cruising along at 25 to 35 mph along a reef line--you know that dive flags are NOT seen, and SMB's are even more impossible to expect the boat to see.
You need a good captain and a boat protecting your dive area. Teaching that SMB's do this is bad logic and will create a false sense of security.

 

[The Chairman]

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.

 

[tphelps]

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.

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.