Marker buoy and spool

[johndiver999]

I don’t think you understand what I’m saying....(not to be rude)

In the Atlantic where I have dived mostly, in calm weather, the waves are regularly 1- 2 m (mostly 1 and1/2 / 2m).

You say you can only keep the DSMB upright if the wind is not blowing, the wind is always blowing dude.

I’m not arguing with you, but please explain how bigger isn’t better when visibility is concerned. To me if there is more to see, you will be more likely to be found and quicker, at least that’s what the coastguard says.

Well if there is just swells then the boat should be able to see you between waves. When it is rough and blowing and white caps, it becomes much harder to see a diver and the smb. But have you tried to keep. 9 ft smb vertical in 15 or 20 mph winds??? I’m not intending to sound rude either, it is an honest question.

After a few attempts, you may understand how difficult they are to manage in white caps and wind. As mentioned, if you are really lost and aircraft are looking for you then a larger smb blown down parallel to the surface may be more visible than a smaller one.

But hopefully the smb will be more often used to assist a boat in finding you and it is a lot better if you can keep it standing near vertical.

The really large ones are bulkier when carrying, so for all those reasons I don’t necessarily think a really large one is advantageous. Simply my opinion, use whatever is best for your conditions.

Edit: I thought of an analogy that might be relevant: Why are all rain umbrellas pretty much similar in size? Why not have a 10 ft diameter umbrella - it would protect you from wind blown rain better, right?

 

[EireDiver606]

Please forgive this embarrassingly remedial question, but how does one get the larger SMBs to stick up out of the water on the surface without tension on the line? Doesn't that require letting some water in to act as a balancing anchor? Or are the larger ones weighted with this in mind?

No, there are closed SMBs and open. Open SMBS have a flap on the bottom which you open and inflate by purging your regs.

Closed SMBs are completely closed and have a nozzle which connects your Low pressure hose (bcd hose) and you can inflate in a second.

There are also more xpexpensive SMBs which are closed and have a mini independent cylinder attached to the cylinder to inflate it.

No you don’t need water in the bottom to keep upright. I know what you mean though. Unfortunately, you have to put pressure on the line from depth or hold it vertical yourself on the surface.

 

[Centrals]

If I dive in really open water I will bring at least THREE smb with different colour.

 

[woodcarver]

Best signaling devices from the searcher’s point of view

This is another thread in this forum. There is a link in it somewhere to a study done by a group in the UK, iirc, trying to determine the best SMB. Both the thread and that study are worth reading to help you figure out what size, and color, SMB you should get. As well as what else should be with you for any dive that is open water and/or has or might have current.
Bigger IS better according to the study. Doesn't take much swell at all to make that 6 footer hard to see. The 3' SMBs in just 1' to 2' swell almost disappear.

 

[EireDiver606]

Best signaling devices from the searcher’s point of view

This is another thread in this forum. There is a link in it somewhere to a study done by a group in the UK, iirc, trying to determine the best SMB. Both the thread and that study are worth reading to help you figure out what size, and color, SMB you should get. As well as what else should be with you for any dive that is open water and/or has or might have current.
Bigger IS better according to the study. Doesn't take much swell at all to make that 6 footer hard to see. The 3' SMBs in just 1' to 2' swell almost disappear.

So do you think I should definitely get a 3m DSMB?

 

[woodcarver]

A 6' is the smallest I have, and is easy to handle and shoot from depth. If you are routinely diving in 3'+ swells, yeah, I would have a 10' with me also. From the bottom of the trough in 3' swell, you only have 7' visible. Probably only need to deploy the big one if you come up farther from the boat than anticipated and can't tell if they can see the smaller one.

 

[Diving Dubai]

So do you think I should definitely get a 3m DSMB?

NO!

As said, I have one. A 3m would really be used on the surface. A 2m you can inflate sub surface with relative ease, then if need be further inflate orally at the surface to wave. Remember a dsmb is used to mark your underwater position (luckly in the British Isles boat know this)

I also recommend an air horn like the dive alert fitted to the LP inflator, and a strobe.

While I don't dive in swells such as you, my diving is remote which fast surface currents which can sweep you some way away quickly (we had a buddy pair swept off a reef and found 2hrs later some 6km / 4miles away)

Your surface signalling device should be something that you are comfortable using and prepared to carry on each dive. Being in Eire you can also benefit from carrying a PLB.

At the end of the day, you as a diver are responsible for being seen, and heard at the surface

 

[EireDiver606]

NO!

As said, I have one. A 3m would really be used on the surface. A 2m you can inflate sub surface with relative ease, then if need be further inflate orally at the surface to wave. Remember a dsmb is used to mark your underwater position (luckly in the British Isles boat know this)

I also recommend an air horn like the dive alert fitted to the LP inflator, and a strobe.

While I don't dive in swells such as you, my diving is remote which fast surface currents which can sweep you some way away quickly (we had a buddy pair swept off a reef and found 2hrs later some 6km / 4miles away)

Your surface signalling device should be something that you are comfortable using and prepared to carry on each dive. Being in Eire you can also benefit from carrying a PLB.

At the end of the day, you as a diver are responsible for being seen, and heard at the surface

Thank you for your reply. Why can you not inflate a 3m or 10” DSMB underwater before you come up? Is it because the volume is too great and will make you more positively buoyant than you can afford? Please explain why?

 

[Diving Dubai]

Thank you for your reply. Why can you not inflate a 3m or 10” DSMB underwater before you come up? Is it because the volume is too great and will make you more positively buoyant than you can afford? Please explain why?

You can of course inflate a 3m dsmb underwater. However because of it's volume you'll never get enough air into it to allow it to be anywhere near fully inflated at the surface before it rises. It will also be quite unmanageable.

You'll end up with a large amount of deflated dsmb on the surface doing nothing.

Better to have a smaller one which you can inflate and will stick up showing your position and then at the surface if necessary using a 3m to attract a boat in an emergency having inflated it at the surface.

a 1.5m dsmb is sufficent in seas from depth or as you approach SS

 

[EireDiver606]

You can of course inflate a 3m dsmb underwater. However because of it's volume you'll never get enough air into it to allow it to be anywhere near fully inflated at the surface before it rises. It will also be quite unmanageable.

You'll end up with a large amount of deflated dsmb on the surface doing nothing.

Better to have a smaller one which you can inflate and will stick up showing your position and then at the surface if necessary using a 3m to attract a boat in an emergency having inflated it at the surface.

a 1.5m dsmb is sufficent in seas from depth or as you approach SS

If you get a closed one with a low pressure hose attached, how will you not be able to inflate it?