Jacket BC or Wing BC

[BDSC]

Cozumel is a place that print magazines talk up as if it had real currents....Compared to pettting zoo dives, yes, they have currents. Compared to Wilderness dives off Palm Beach, Cozumel is a petting Zoo, and the Cozumel divers don't really know Drift diving as an advanced skill. We could teach the Mexicans, but there is no incentive for that

You must have never dove Barracuda Reef.

 

[Splitlip]

I googled Barracuda.
Barracuda Reef, Cozumel

If a snorkeler moves at the same speed as a diver on the bottom, you're in a different world from the sites Dan and DD are discussing. The link above sounds more like Boynton. Not that there's anything wrong with that

 

[-hh]

I googled Barracuda.
Barracuda Reef, Cozumel

If a snorkeler moves at the same speed as a diver on the bottom...

The article states otherwise: "...the current at the surface is often different than at depth".

It isn't a ton of fun to be the guy holding the float in such conditions, as these varying currents in the water column will drag one around, which can serve to break up a buddy team or group. Using a surface chase snorkeler is one approach that works adequately in high visibility waters.

The link above sounds more like Boynton. Not that there's anything wrong with that

The first dive does ... it was characterized as being "~1 knot".

But the second dive (a few hours later on the same day) was "5 knots".

Although not its intent, the trip report actually serves as a good illustration for how time of day can have a very strong influence on a dive. This is also why a good OW-I training class includes education on dive planning, such as to schedule a dive for during "slack tide", etc.


-hh

 

[SnorkelLA]

This is a never ending argument- one I've had my hand in a fair few times. I personally prefer Jackets because they WORK for me. I'm the kind of guy with tons of gadgets and useless dewhickeys to dive with and I find my Mares Dragon works best FOR ME. Lots of tec/commercial divers that may not use all the crap I do find them great for keeping trim in the tight environments they tend to live in (I wish I had kahoonas sizeable enough to go where some of them go). I've used both, and in my opinion, with proper practice, you can be great with eaither one.

I kind of fall middle of the road, as I'm a jacket user, wearing Scubapro Jet fins (something alot of GUE/DIR divers preach) and I agree, they are fantastic. I can't get this kind of control with Aeris Velocity X3s I had (but that's beside the point)

 

[BDSC]

I googled Barracuda.
Barracuda Reef, Cozumel

If a snorkeler moves at the same speed as a diver on the bottom, you're in a different world from the sites Dan and DD are discussing. The link above sounds more like Boynton. Not that there's anything wrong with that

I've dove the site twice. One day we had a reasonably strong current but perhaps no more than some of the other southern sites I have done in Cozumel. The second time I dove it the current was ripping! And I mean ripping. I don't care what anyone would have been wearing that day you were going with the flow and there was nothing you could do about it. Of course I thought it was fun and it was. It was three divers and one DM/Instructor. After about 30 minutes he sends up his surface marker and we keep floating along. Finally when it's time to do our safety stop I notice how choppy the water was above. Finally we surface and what a shock. I had no idea we had drifted that far from the island. We had to be a few miles from shore. I can see why they say the next stop is Cuba.

 

[Splitlip]

The article states otherwise: "...the current at the surface is often different than at depth".

It isn't a ton of fun to be the guy holding the float in such conditions, as these varying currents in the water column will drag one around, which can serve to break up a buddy team or group. Using a surface chase snorkeler is one approach that works adequately in high visibility waters.




The first dive does ... it was characterized as being "~1 knot".

But the second dive (a few hours later on the same day) was "5 knots".

Although not its intent, the trip report actually serves as a good illustration for how time of day can have a very strong influence on a dive. This is also why a good OW-I training class includes education on dive planning, such as to schedule a dive for during "slack tide", etc.


-hh

I admit I missed the 5 knot.

My point about the snorkeler was the difference in currents between the bottom and the surface. I just can't see a snorkeler in local conditions being able to hang back with divers on the bottom.

 

[-hh]

I admit I missed the knot.

No problem.

My point about the snorkeler was the difference in currents between the bottom and the surface. I just can't see a snorkeler in local conditions being able to hang back with divers on the bottom.

Understood, although that's still making assumptions about the current profile(s): it is also possible for there to be a surface current to be running at odds to a bottom current.

And of course, that old report didn't mention a lot of details about this "chase snorkeler". For example, I assume that the snorkeler was a paid crewmember, not a random tourist customer. Similarly, it isn't unheard of to tow snorkelers behind a boat, out on the tag line, for doing things like a Search & Recovery grid, Lobster Hunting, Site Exploration, etc. Just need to work out a few hand signals for the snorkeler to direct the boat's direction, and you have a decent start at how to make this technique be able to work.

In any case, having excellent in-water visibility is required to make this "snorkeler overwatch" technique work at all, which might be a factor that excludes your Florida coast region from considering it. And YMMV on what "excellent viz" means, but in this case, they're probably referring to 100 ft as a "bad day" absolute minimum.


-hh

 

[danvolker]

Lets go back to the cycling analogy, because it really does apply better than any other conceptualization attempted so far.

In looking at the universe of scuba divers, this is much like the universe of cyclists. Most cyclists will pedal at 10 mph to 15 mph, as a sustainable pace they can be comfortable with....this relates to most scuba divers, that dive the destinations advertised heavily in the Print magazine...places aimed at the masses. This group consisting of MOST scuba divers ( people that do not train several days per week specifically for cycling or scuba fitness) will swim comfortably at .2 to .5 mph, and if they are forced to, can run up to a maximum sustainable for maybe 10 minutes or around 1 mph...pretty much doubling the effort they put out at .5 mph. This group will not feel the effects of a high tech aero bicycle, where the drag factors come into play around 21 to 24 mph, and exaggerate from then on. This is also the huge floppy BC or somewhat streamlined vest bc wearer, a group that will not reach enough speed in the water to create enough differential of drag between .2 and .5 mph ----they "might" get an inkling of drag differences if they had to sustain 1 mph for long, but they would say that this is not what they got into diving for, and would have little interest in this. This group, if on bikes, is happy with hybrids or mountain bikes on the road, or normal road bikes if they fit well. They feel little difference from one bike to the other, performance wise...the main criteria for them is comfort and fit.

Next....the cyclists that can comfortably sustain 18 to 22 mph, where 18 feels slow and as a resting pace. This in scuba is the group that will pace easily( resting heart rate) at 1 mph, and utilize big kick and glide, along with multiple kick styles. In cycling, this group chooses performance bikes, they would hate hybrids, all will get custom pro level Bike fittings, and can easily tell the difference from one bike to the next. In scuba, this group can use Vest BC's that are very streamlined, and achieve phenomenal results with them in currents up to 2 to 3 mph. This group stays fit, whether for cycling or scuba, and this fitness is leveraged in scuba. This group can put on a bp/wing, and when it is custom fit to them by a pro, they will feel a big difference from a pufferfish style bc, but may not feel as much difference between the bp/wing and a really streamlined vest bc.

Then, there are the cyclists that really race. They will run at a low aerobic heart rate at 22 mph, and can sustain 25 mph by themselves for a whole hour, or even faster. They are litterally more than twice as strong /powerful as the group below them, and have nothing whatever in common with the first group. In scuba, this group can pace at 1.5 mph as easily as the 2nd group can pace at 1 mph, but they would not typically do this--most divers at this level would be perfectly trimmed and attempting to be slick in the water, with no energy expending....however, when conditions arise which would cause group 2 or group 3 to exert to a high output pace, this 3rd group can achieve speeds much faster than group 2, ( instead of a sustain max of 2.5 mph, they may reach 3mph or 3.5....which underwater is like the cyclist going 26 to the cyclist that maxes at 21.)
This 3rd group will experience all the nuances of the bp/wing, and this group will experience major efficiency ( less drag issues) with the bp/wing, whether in cruising easy, or in swimming fast to deal with some issue. This group will be righteous about the differences they experience between the bp/wing and the vest BC, particularly IF they have dive sites they frequent where large currents or big marine life presents situations where the drag differences become apparent with higher swim speeds and bigger currents. Both group 2 and group 3 will appreciate the differences in propulsion between fins, but group 3 will have entirely different appreciations than group 2, due to power and skill levels in their own propulsive abilities.

The dive industry caters almost exclusively to group one.....specialty mfg's cater a little to group 2. Group three is so small it is more like it's own club, with little or no mass marketing ever presented to it, but with considerable internet discussions which have been crucial to this group in their attempts to optimize their experiences.

 

[mictrik]

Lets go back to the cycling analogy, because it really does apply better than any other conceptualization attempted so far.


In looking at the universe of scuba divers, this is much like the universe of cyclists. Most cyclists will pedal at 10 mph to 15 mph, as a sustainable pace they can be comfortable with....this relates to most scuba divers, that dive the destinations advertised heavily in the Print magazine...places aimed at the masses. This group consisting of MOST scuba divers ( people that do not train several days per week specifically for cycling or scuba fitness) will swim comfortably at .2 to .5 mph, and if they are forced to, can run up to a maximum sustainable for maybe 10 minutes or around 1 mph...pretty much doubling the effort they put out at .5 mph. This group will not feel the effects of a high tech aero bicycle, where the drag factors come into play around 21 to 24 mph, and exaggerate from then on. This is also the huge floppy BC or somewhat streamlined vest bc wearer, a group that will not reach enough speed in the water to create enough differential of drag between .2 and .5 mph ----they "might" get an inkling of drag differences if they had to sustain 1 mph for long, but they would say that this is not what they got into diving for, and would have little interest in this. This group, if on bikes, is happy with hybrids or mountain bikes on the road, or normal road bikes if they fit well. They feel little difference from one bike to the other, performance wise...the main criteria for them is comfort and fit.

Next....the cyclists that can comfortably sustain 18 to 22 mph, where 18 feels slow and as a resting pace. This in scuba is the group that will pace easily( resting heart rate) at 1 mph, and utilize big kick and glide, along with multiple kick styles. In cycling, this group chooses performance bikes, they would hate hybrids, all will get custom pro level Bike fittings, and can easily tell the difference from one bike to the next. In scuba, this group can use Vest BC's that are very streamlined, and achieve phenomenal results with them in currents up to 2 to 3 mph. This group stays fit, whether for cycling or scuba, and this fitness is leveraged in scuba. This group can put on a bp/wing, and when it is custom fit to them by a pro, they will feel a big difference from a pufferfish style bc, but may not feel as much difference between the bp/wing and a really streamlined vest bc.

Then, there are the cyclists that really race. They will run at a low aerobic heart rate at 22 mph, and can sustain 25 mph by themselves for a whole hour, or even faster. They are litterally more than twice as strong /powerful as the group below them, and have nothing whatever in common with the first group. In scuba, this group can pace at 1.5 mph as easily as the 2nd group can pace at 1 mph, but they would not typically do this--most divers at this level would be perfectly trimmed and attempting to be slick in the water, with no energy expending....however, when conditions arise which would cause group 2 or group 3 to exert to a high output pace, this 3rd group can achieve speeds much faster than group 2, ( instead of a sustain max of 2.5 mph, they may reach 3mph or 3.5....which underwater is like the cyclist going 26 to the cyclist that maxes at 21.)
This 3rd group will experience all the nuances of the bp/wing, and this group will experience major efficiency ( less drag issues) with the bp/wing, whether in cruising easy, or in swimming fast to deal with some issue. This group will be righteous about the differences they experience between the bp/wing and the vest BC, particularly IF they have dive sites they frequent where large currents or big marine life presents situations where the drag differences become apparent with higher swim speeds and bigger currents. Both group 2 and group 3 will appreciate the differences in propulsion between fins, but group 3 will have entirely different appreciations than group 2, due to power and skill levels in their own propulsive abilities.

The dive industry caters almost exclusively to group one.....specialty mfg's cater a little to group 2. Group three is so small it is more like it's own club, with little or no mass marketing ever presented to it, but with considerable internet discussions which have been crucial to this group in their attempts to optimize their experiences.

WOW! I find your analogy and the over all premise outlandish. The backplate & wing is not more streamlined than a proper fitting Stabilizer jacket. If you are putting much air in these things you are poorly weighted and this will have a far greater effect on streamlining than any other source. NO option for buoyancy compensation truly stands out as all around better; they all have their "UP's & downs". The notion that a backplate and wings is akin to a race bike with high end materials and components is laughable. It is just an air filled sack at your back instead of around you or at at your sides. Pluses for this include modularity, options for high lift capacity (IF NEEDED, MOST DO NOT!!!), a clean uncluttered front and excellent horizontal stability when the bladder is inflated at any ratio of it's capacity. Streamlining is NOT one of it's pluses as so many people seem to advocate. The differences in drag of a backplate wings relative to a stab jacket is almost zero. Even an 18lb wing still has a backplate that sticks out further from the back than the small stab jackets backpack. But comparing equivalent lift which is 60lbs for a Stab jacket in Large to a 60lb wing you will not find any significant difference in drag. in fact my bet is that the stab jacket when only lightly inflated is more streamlined than the equivalent BP/Wing setup. I bet the divers body type is the largest component of underwater drag. I know that when i just use a backpack with a single tank that I am more streamlined than with any BC. I think the Cousteau team way back in the 70's utilized drag reducing tank cabinetry containing high pressure cylinders of a small form factor. This along with tight fitting wet-suits and fit divers were probably the most "streamlined" condition I have seen in SCUBA.

 

[Zieg]

WOW! I find your analogy and the over all premise outlandish. The backplate & wing is not more streamlined than a proper fitting Stabilizer jacket. If you are putting much air in these things you are poorly weighted and this will have a far greater effect on streamlining than any other source. NO option for buoyancy compensation truly stands out as all around better; they all have their "UP's & downs". The notion that a backplate and wings is akin to a race bike with high end materials and components is laughable. It is just an air filled sack at your back instead of around you or at at your sides. Pluses for this include modularity, options for high lift capacity (IF NEEDED, MOST DO NOT!!!), a clean uncluttered front and excellent horizontal stability when the bladder is inflated at any ratio of it's capacity. Streamlining is NOT one of it's pluses as so many people seem to advocate. The differences in drag of a backplate wings relative to a stab jacket is almost zero. Even an 18lb wing still has a backplate that sticks out further from the back than the small stab jackets backpack. But comparing equivalent lift which is 60lbs for a Stab jacket in Large to a 60lb wing you will not find any significant difference in drag. in fact my bet is that the stab jacket when only lightly inflated is more streamlined than the equivalent BP/Wing setup. I bet the divers body type is the largest component of underwater drag. I know that when i just use a backpack with a single tank that I am more streamlined than with any BC. I think the Cousteau team way back in the 70's utilized drag reducing tank cabinetry containing high pressure cylinders of a small form factor. This along with tight fitting wet-suits and fit divers were probably the most "streamlined" condition I have seen in SCUBA.

Oh boy! You've done it now.