Freediving fins might help

[clownfishsydney]

If you actually look at a current from the surface and work out its strength (by calculating how long a twig or bubble takes to move a certain distance), then dive in it, you will know that a scuba diver with normal fins can only hold their own against a two knot current for a short time before becoming exhausted. Anything more than that, you will go backwards.

If you work out the how fast an Olympic swimmer goes, then you will soon realise that currents more than this are impossible to swim against. For example, the current world record for 1500 metres is a bit under 15 minutes. Make it 15 for our purposes. That equals 100 metres every minute. This is 6 km/h, or 3.5 mph or 3.24 knots. Of course, they do not have fins on but also, they are not wearing a wetsuit or mask or BCD or tank or regs which all create drag.

Therefore, the apparent claim above that you can swim against a 3 to 5 knot current is not correct. In my experience, anything over one knot becomes impossible except for short distances or for an Olympic standard-fit diver.

And yes, I have dived in currents that it was impossible to swim against and even hold your own against (Solomon Islands) and it does not matter what fins you have, you will still not be able to do it.

The fact is, the type of fins is irrelevant to what happened here and I suspect, has had little to do with all but a handful of dive incidents.

 

[danvolker]

5 knots, 5.8 mph, 8 and 1/2 feet per second. How long can you swim against that?

Your making the assumption that it would have been necessary to swim directly against a 5.8 mph current. Sideways to it is not so hard, and you can make very good headway sideways with freedive fins or Extra Force fins, but almost nothing will happen if splits are on...the sideways vector destroys the forward thrust for the splits.

There is also the bottom if not extremely deep, and if they are not yet OOA, where you can go hand over hand against a 6 mph current ( it is not typically over half of this right at the belly rubbing the bottom point)....but again, you would have kicking assist with the hand over hand and freedive fins, but NO assist with splits.

I don't see how you let yourself get to the point that the only direction you can head for, is directly against a 6 mph current on the surface--and this is not going to be effective as a surface strategy for any distance much over the length of a boat( so not even in the discussion). Why not a vector off to some point of land that could easily have been made? It sounds like they were not ridiculously far from land--there should have been an angle they could have taken, if they had functional fins and functional propulsion.

 

[Zippsy]

@all:
Could you please stop this ridiculous discussion about scuba or freedive fins?
After all at least one diver died here and trust me, with the currents that you can experience in some parts of Indonesia it just doesn't matter which fins you have as they are too strong to kick against for the time needed to get to safety.

Andy

Andy is a genius. You really need to buy him a beer or, at minimum, listen to him because this is good advice. Discussing fin type effectiveness in this thread is just really silly.

 

[gee13]

...And insensitive given someone had died, a group had gone through near death trauma due to a boat not being present at the dive exit... and the petty discussion of fin type needs to be brought up ?

The testament that 5 survived and lived to tell a tale, that they DID get to land, then to find get onto jagged slippery rocks amongst a steep hanging clifface with 3m swell and waves after being in strong surface currents then survive another 3 days with little water and no food...

This is a 'typical shoreline' of Nusa Penida that the survivors had to negotiate.

 

[gekodivebali]

I wish moderators would intervene. You guys trying to sell fins on a thread about an incident where a diver died disgust me...

 

[tedshark]

I wish moderators would intervene. You guys trying to sell fins on a thread about an incident where a diver died disgust me...

No one is trying to sell anything on here, this happens once too many times, where a diver finds himself in trouble because they use something that is doomed to fail in a time of need.
This is great the 6 survived this ordeal, and it would be great if we could learn from them, but chances are low that we will from the survivors.

 

[The Wolf]

I call BS to that....we get 3 to 5 mph currents all the time in Palm Beach.....it's not like we don't know currents.....and one thing that is obvious, is that there are MAJOR differences between how divers on charter boats are able to go against currents, or crosswise to them if desired or required. Splits being the most ineffective.

If fit divers could not do a bad day with freedive fins, then normal divers could not do this on a normal day.....If you are talking 8 and 10 mph currents, then how in the he&& does a charter operator justify operating in it?

I have done lots of diving around Fiji, with freedive fins ( even left a pair for the DM when I left)....and they allowed me to do anything I wanted to, at any time, at any site.

This is a nonsense of the dive industry, thinking that all fins are equal, and that divers don't NEED to be able to have REAL Propulsion if conditions dictate it.....While fitness does play here....put a "fit diver" in splits, in a huge Palm Beach current, ask him to go sideways or up current, and he is a leaf in the wind...put freedive fins on the same fit diver...or for that matter, Extra Force Fins, and the fit diver will blast up current with no problem, or across current.
We see this all the time...fortunately in Palm Beach we have great drift boat operators, so that all these people with split fins are not going to ever need to fight a current--the boat will get them wherever they are taken to.

I don't want to spoil this thread given a diver has died and another remains missing but..you don't know what you're talking about.

---------- Post added February 19th, 2014 at 06:55 PM ----------

Your making the assumption that it would have been necessary to swim directly against a 5.8 mph current. Sideways to it is not so hard, and you can make very good headway sideways with freedive fins or Extra Force fins, but almost nothing will happen if splits are on...the sideways vector destroys the forward thrust for the splits.

There is also the bottom if not extremely deep, and if they are not yet OOA, where you can go hand over hand against a 6 mph current ( it is not typically over half of this right at the belly rubbing the bottom point)....but again, you would have kicking assist with the hand over hand and freedive fins, but NO assist with splits.

I don't see how you let yourself get to the point that the only direction you can head for, is directly against a 6 mph current on the surface--and this is not going to be effective as a surface strategy for any distance much over the length of a boat( so not even in the discussion). Why not a vector off to some point of land that could easily have been made? It sounds like they were not ridiculously far from land--there should have been an angle they could have taken, if they had functional fins and functional propulsion.

Try doing this in the middle of a storm with big waves and currents and dark conditions....it's just amazing how some people think it's all so easy until you are put in that situation and then have to not only overcome fear and desperation but trying to survive.

And take into account they were tired and probably exhausted after their 3rd dive and they were women trying to swim against currents...how long can you keep going before you are flat out tired and can't kick or battle against the current even with a BCD?

Geez, please, give it a rest won't you.

 

[danvolker]

So what should have been done differently (apart from the freediving fins rubbish)?

From what I read the boat dropped anchor while on a site with some current, instead of following the divers?
The weather changed and there was no warning to the divers. I've dived in situations where it was agreed that engine revs would mean go up.
Also, don't they pay attention to weather forecasts? Or are they completely out of communications in those areas?
Boat not having fuel to search the divers.
Huge delay to report them as being lost!

You show a shocking lack of awareness over REAL issues involved in a tragic event where divers were swept away....How can you NOT be aware that it is typical for Freedive fin wearing divers, to effortlessly swim at twice or even 3 times the diving pace, of split fin wearing divers? When MANY Divers see such ridiculous disparities, they start whining about how divers should not be swimming fast, and that diving is all about swimming slow--this making the split fin users feel that they are just fine with their slow swimming ..... I have always said that divers should have fins with much more propulsive potential than splits--not so they can fly around at high speed during all dives--but so that IF THEY DO HAVE AN EMERGENCY, THEY CAN DEAL WITH IT. I don't sell fins. What I want to do is get divers to make smarter choices, and this includes getting them to stop this inane refusal to see why divers should NOT be using fins with poor propulsive potential for emergency conditions.

I absolutely believe with the right gear on, and the right decisions made, these divers could have had a much better outcome....It sounds like the moronic operators of the boat made a return to the boat impossible, so the RIGHT decision, would have been scanning the land on the horizon, and choosing what direction to swim so that the BEST likely outcome could be reached....It would mean getting themselves to land--and NOT counting on some other boat.

I do see that there are many land points with intense cliff approaches that would mean they are NOT good places to aim for....A local would have to weigh in on from where they realized they would not be picked up, as to WHERE the direction they swam to should be....and on how fast they would need to average.

To reiterate a major aspect of this again....one of the WORST THINGS about many of the models of Split fins, is the way that they lose their ability to create effective forward propulsion, when a diver attempts to swim perpendicular to a current. In many dives off of Palm Beach, I have been in groups on the deep side of a reef on a drift dive, and the group will elect to swim up the wall and across the crown to the shallow side of the reef, and then spend the next 30 minutes drifting down current along the shallow inshore ledge....the problem that many of the split fin wearers have, is that the divers with normal paddle fins just begin swimming sideways or at 45 degrees to cross---and they are swimming sideways to a 2 to 4 mph current ....and they just begin pulling away from the split fin divers...that thrash away to no avail....they had experienced no problems with the shared pace when drifting down current in the first phase of the dive on the deep ledge, but on needing to cross a current, they had no ability to do so....one typical result is a stronger diver with paddles or freedive fins, actually towing the split fin divers across the reef crown.

Ignoring defective gear is NOT helping anyone, and that is one of the reasons for this forum.

 

[Redshift]

The real issues were the ones that actually happened, not the hypothetical "they could have had freediving fins". They could also have had DPVs. If you notice, all the points I mentioned were about things that could have been done differently at the time and that could have prevented the outcome. Having different fins is not an option. Neither is to ban divers without freediving fins. But behaviours and procedures can be changed.

But if you want to go into the fin business...
First of all, you made your statements without any knowledge of the currents experienced at the site. It is well possible that the freediving fins would have made no difference.

You assume that they were using split fins and that they are the worst kind. You should take a look at some speed comparison tests.
Still, I agree, freediving fins should still be faster, but they'll lose efficiency when used to propel a bulky diver with scuba gear, just like a fast car loses efficiency when towing a trailer when compared to a truck. And not even all freediving fins would be appropriate.
Furthermore, they require divers to be more fit. Not for their normal dives, but if situations like these arise. And then what happens if they are not? They won't sustain speed for any considerable period, they will get cramps, they will be in worse state at the end without achieving anything. So now we are banning from diving a)divers without freediving fins and b)divers not fit enough to sprint with them.
Should divers be in good physical shape? Of course! Is that the same as being able to sprint for several minutes? I don't think so. And requirements like that would be worse for the sport and even general health of people who are now enjoying this sport.

Still, moving along, these divers had indeed freediving fins and were all top shape. What next? In the report they said they couldn't see the boat, so no swimming towards it. Swimming to shore could have worked if the current was parallel to it and there was a long enough shore. If it was pulling them away, they'd still be carried to sea.

And what would you do to all the divers who need some kind of foot protection for walking?
How many more people wouldn't get hit in the face due to long fins? And having a harder time to turn, swim backwards, in tighter spaces, not hitting corals, etc? All that because someday they might happen to be in a current which is too strong for normal fins yet, not too strong for freediving fins (what's that, 1-2 knots?), hoping they can withstand an effort they are not used to and that all other best practices in place have failed?

And you see your opinion as being the truth, even when other people here disagree. They are clearly wrong. Even those who have dived in the area, those who have dived in strong currents, clearly me who by the way am a free diver (and even the scuba fins in my avatar are the cressi master frog which are almost free diving fins) and was a swimmer for many years. Yet, I am wrong.

 

[Zippsy]

Thanks Natasha but that report seems incomplete. It fails to mention which brand of split fins she was wearing.