Who Uses their SMB and Deploys it At Depth Before Ascending to the surface

[GrimSleeper]

I did wonder if we were at cross purposes...

 

[danvolker]

This post was in response to a post I read of a woman who near had her knee cut off from just such an accident. The boat that caused it was THEIR dive boat. AS she surfaced he started the motor and moved forwards and hit her. had she of used an SMB there was a fair chance that she would not have been hit.

I agree the SMB is not a big protective shield warding off everything around you, however it does give a moving boat "some" chance to see you and give prior warning before you break the surface.

With regard to the noise, the woman did not hear anything, she is unsure why, perhaps because of many boats in the area, perhaps because he started the engine and wasn't moving at speed, but in any regard, saying you WILL hear every engine and boat is like saying an SMB will prevent every collision. She had a hood on and perhaps this also restricted her hearing.

With regard to shooting for the surface quickly to get up and look around, I see as crazy and could cause an embolism or the bends. The last 5 metres of the dive should be the slowest ascent. ALL diving related comments recommend this. I would never shoot to the surface from 5 metres and in particular after doing a long decompression dive. I would always have my SMB deployed and come up slowly.

Often the charter boat is anchored up and divers have drifted away from the anchor or down line, hence the need for an SMB for location and better protection. Its expected in many places in OZ to deploy your SMB if not coming up an anchor line. Also one guy on a boat drifting with you can only see a limited area and so every bit above the water helps this process.

As I said previously, an SMB is not a protective canopy, however it is better than a black hood in dark water.

So then let me ask another question, who thinks shooting to the surface from your safety stop or last deco stop is a good thing so as not to be hit by a boat on the move? personally I think not and would never recommend that to anyone. It might (and I say might) save you from the boat, but the increased risk from a dive related illness is much greater.

But that is only my opinion and you clearly have a different approach. I guess I will dive my way and you yours.

Hoods leave a diver deaf underwater.....if you have to dive in cold water, then you need to know you are diving without one of your senesce--you are handicppped.
I don't dive this way in Florida or the caribean, or Fiji...

I always hear whether or not there is boat traffic....the fact that this woman heard nothing, is absolutely consistent with what we see from hooded divers here.

If I or my group is not towing a dive flag ( which is the norm here in Palm Beach--towed flag or towed torpedo for us with flag) , and we know we are coming up well away from the other dive groups, one of us will shoot a bag....my point is that this is not done with any expectation that it will be effective in warding off boats. The expectation is, and must be, that there will be a boat coming right at you on the surface, if you hear any boats at all---and that the smb is being ignored.
So you do a nice long safety/deco stop at 10 feet--and when you feel you have the safety margin in plenty of stop time, you deflate, and kick hard to the surface, ready to perform an emergency return to 10 feet or deeper if some jerk is heading your way. If it is safe, you can wave your buddies up to the surface, and if you are concerned about bubbles from this fast surfacing, you have only been up about 15 seconds to 25 seconds total as your friends hit the surface--so you could drop yourself back down to 10 or 15 feet if you have a concern about hyper saturation. You could hang there for 5 to 10 more minutes if you needed. Keep in mind I have been doing this in my Palm Beach diving since the early 80's, and the danger has always been boaters--not bubbles.

To one other poster in this thread....we have very few sailboats out over the reefs--maybe 1 for every thousand fishing boats/speed boats. And yes, I have had a big sailboat go over head, and I saw it--rather than heard it, on my 360 degree spin. It was a shock, but fortunately the visibility was about 80 feet that day, and I saw it with time to spare in jackknifing and getting down below his keel/centerboard, whatever it was.
That was one time, in 3 decades--for the sail boat issue

The towed torpedo with a flag is by far my best defense from boaters, and best way to help my own charterboat protect us by easily tracking us. Here is one example....though I like mine alot more than this one( cona't find it this moment online) Omersub Atoll Float

On descent, you let this out with a nice reel, and if you want to stop on the bottom, you have a hook on the reel, and can hook off on a rock or cranny.

The flag is regulation height, and the torpedo is rigged (by me) to be towed so as to float flat on the surface with the line pulling down on it, and it does so with essentially no drag at all, when compared to a standard flag float( which is very high drag). In perspective, if you toss a flag float off the back of the boat going 25 mph, it could easily rip right out of your hands, and will be very hard to hang on to....the torpedo would just fly along the surface, with very little effort in holding it.

 

[Peter69_56]

Hoods leave a diver deaf underwater.....if you have to dive in cold water, then you need to know you are diving without one of your senesce--you are handicppped.
I don't dive this way in Florida or the caribean, or Fiji...

I always hear whether or not there is boat traffic....the fact that this woman heard nothing, is absolutely consistent with what we see from hooded divers here.

If I or my group is not towing a dive flag ( which is the norm here in Palm Beach--towed flag or towed torpedo for us with flag) , and we know we are coming up well away from the other dive groups, one of us will shoot a bag....my point is that this is not done with any expectation that it will be effective in warding off boats. The expectation is, and must be, that there will be a boat coming right at you on the surface, if you hear any boats at all---and that the smb is being ignored.
So you do a nice long safety/deco stop at 10 feet--and when you feel you have the safety margin in plenty of stop time, you deflate, and kick hard to the surface, ready to perform an emergency return to 10 feet or deeper if some jerk is heading your way. If it is safe, you can wave your buddies up to the surface, and if you are concerned about bubbles from this fast surfacing, you have only been up about 15 seconds to 25 seconds total as your friends hit the surface--so you could drop yourself back down to 10 or 15 feet if you have a concern about hyper saturation. You could hang there for 5 to 10 more minutes if you needed. Keep in mind I have been doing this in my Palm Beach diving since the early 80's, and the danger has always been boaters--not bubbles.

To one other poster in this thread....we have very few sailboats out over the reefs--maybe 1 for every thousand fishing boats/speed boats. And yes, I have had a big sailboat go over head, and I saw it--rather than heard it, on my 360 degree spin. It was a shock, but fortunately the visibility was about 80 feet that day, and I saw it with time to spare in jackknifing and getting down below his keel/centerboard, whatever it was.
That was one time, in 3 decades--for the sail boat issue

The towed torpedo with a flag is by far my best defense from boaters, and best way to help my own charterboat protect us by easily tracking us. Here is one example....though I like mine alot more than this one( cona't find it this moment online) Omersub Atoll Float

On descent, you let this out with a nice reel, and if you want to stop on the bottom, you have a hook on the reel, and can hook off on a rock or cranny.

The flag is regulation height, and the torpedo is rigged (by me) to be towed so as to float flat on the surface with the line pulling down on it, and it does so with essentially no drag at all, when compared to a standard flag float( which is very high drag). In perspective, if you toss a flag float off the back of the boat going 25 mph, it could easily rip right out of your hands, and will be very hard to hang on to....the torpedo would just fly along the surface, with very little effort in holding it.

I suspect where you are diving there is significant boat traffic, whereas all the places I have dived to date there has been little traffic. I do take your point though.

 

[DevonDiver]

The majority of entry-level technical divers I teach don't have skills/experience with DSMB deployment. It'd be nice if they did...

 

[Peter69_56]

I agree, the tech instructor I had was surprised that we both had used our SMB regularly, as he said most normally don't deploy it properly and need tuition and a number of attempts before demonstrating they are competent.

 

[Edward3c]

I see the smb ONLY as a visual aid for THE Dive Boat you are diving off of, to keep track of it's divers with....just like a towed float on a drift dive. This is the ONE BOAT that will care about the smb, and actually see it with reliability.

Its much more than that. It gives the diver(s) a second reference of their ascent speed which is easily controlled. Using a mark on the line at, say, 6m any deco stop can be done using it as a reference rather than being fixated on a computer/depth-gauge. Also useful when making a blue-water assent with a less experienced diver.

The OP and most of the divers learning the SMB deployment skill, seem to think the SMB will magically ward off errant boaters that would otherwise cross over your head at full speed....This is seriously defective thinking.

A fishing boat traveling at 20 to 30 mph, in seas of 2 feet or greater, is highly UNLIKELY to see a full sized dive flag and float until practically the moment they run over it--which is why we have charter boats protecting our dive area, and ready to play chicken with approaching boats, before they enter into our dive area. And SMB is far less likely to be see by a rapidly approaching boat.

What about a very slow boat approaching? The question would be why would they be going slow way out over a reef? In any event, the diver skill that is critical here, is the LISTENING SKILL. That at the 20 to 10 foot stop, the divers are listening for boats, and gauging how busy the surface is with boaters.

Your opinion, which I don’t subscribe to.

The skill needed, is knowledge of what the doppler shift sound is like, that differentiates a boat coming toward you--from one motoring away from you....and the skill in deciding if the boat noise you hear is a boat that is very close, or a very long way away.

In my own drift diving, on the dives I have done when not towing a surface float ( for my boat to follow), at my ten foot stop, I am listening for the point where I hear no boats in any effective range to run over us, and then when this moment is reached, I do a deflation of the wing/bc to negative, and then swim up hard and fast to the surface, doing a 360 degree spin and scan as I surface. On surface, the 360 scan will instantly alert me to any boats approaching--if I had an smb deployed, I would need to be doing exactly the same scanning. If there is a rapidly approaching boat, my wing/bc is already deflated, so I can jack knife and instantly be down to 10 feet in a second or two.

Totally against all the guidance I’ve seen from many agencies. BSAC recommend 1 minute from 6m to the surface.

I carry one on all dives and practice its deployment, maybe every 5^th session, because when I want to deploy in anger I want to be proficient.

Its use and deployment is built into BSAC's core training for Sports Divers and Dive Leaders.

 

[Rich Keller]

I have an SMB, and I never said divers should not deploy them.... I said they should not trust the SMB to ward off boats.....That is true in Florida, and if I was in Norway, I would not trust boaters either.
You are free to trust boaters anywhere you like.

Many boaters do not know what a dive flag is for and far fewer will know what a SMB is for. I think that a SMB will attract boats to your position rather then deter them. Some fool is going to see this thing pop up and come over to have a look. I have a SMB & reel that I take on charter boat trips but I use them differently then most people. If I need to signal the boat I came from I will deploy it on the surface. If I am left behind I will use it to mark my position, attach the reel to my weight belt, drop the belt so it anchors me in the first place someone will come back to looking for me.

 

[MXGratefulDiver]

Hoods leave a diver deaf underwater.....if you have to dive in cold water, then you need to know you are diving without one of your senesce--you are handicppped.

Not true ... I've done roughly 3,000 dives while wearing a hood ... 5mm or 7 mm ... and can hear just fine while wearing it underwater. A hood impairs your hearing above the surface, but far less so below. I can hear a boat approaching from a pretty far distance while wearing one. I'll grant that you can probably hear better without one, but to characterize it as depriving you of your sense of hearing is an overstatement.

... Bob (Grateful Diver)

 

[danvolker]

Not true ... I've done roughly 3,000 dives while wearing a hood ... 5mm or 7 mm ... and can hear just fine while wearing it underwater. A hood impairs your hearing above the surface, but far less so below. I can hear a boat approaching from a pretty far distance while wearing one. I'll grant that you can probably hear better without one, but to characterize it as depriving you of your sense of hearing is an overstatement.

... Bob (Grateful Diver)

Bob, I think I can say this as well as you can..... I have dived around thousands of people..... at least as many as you have......When they wear a hood, their hearing is severely impaired.
You can rationalize all you want, but unless the hood is lycra or acoustically invisible ( unlike 5 mil or thicker hoods), then the diver wearing this has hearing loss.

 

[MXGratefulDiver]

Hearing loss ... yes, some. Deaf? Certainly not.

Don't overstate, Dan ... I've been wearing a hood while diving for the past 12 years ... averaging about 275 dives per year while wearing one. And I've never experienced "deaf".

Water conducts sound extremely well ... and while (as I said previously) you can probably hear better without one, you don't lose your hearing because you're wearing a hood.

I can hear well enough to know when my buddy's speaking or humming into their reg ... and can certainly hear a boat coming from a fairly long distance away. And at my age, my hearing's not as acute as it used to be.

... Bob (Grateful Diver)