Trip Report Raja Ampat, Live Report, Nov. 7-Dec. 7, 2023

[Dan]

And what did you folks do, after clinging to the wall? How did you folk get out of it?

It usually does not last very long. Just wait until it dissipates to a level where you can get way from the downcurrent. The key is to get there ASAP so you don't get there at a very deep end of the wall and consuming gas rapidly.

In this case, it happened at the beginning of the dive. So you have plenty time and gas to breathe on, calm yourself down. Unless you are too slow to move and ended up at the deep end (137' or 42m), then panic sets in, breathing even harder and rapidly sucking the tank dry. Nothing good will be coming out of it.

 

[CWK]

I have been on a wall in Indonesia with very strong downcurrents before. As mentioned before, there are no hard and fast rules for nature. When she's feeling feisty, she does what she wants. Firm instructions were given to not go away from the wall if it ever does occur because the downcurrents can persist away from it and if you did move away from it, you would have nothing to hold onto or climb up on and can get yourself in trouble really quickly. For that reason, and in Indonesia, having a wall is a good thing and I agree about moving towards it. In some parts of the world, it is suggested to move away from the wall because the downcurrents in other places are often more pronounced at the wall. In any case, always pay attention to briefings.

There is a site in RA called Manta Ridge. Eveey time that I have been there, the ore dive instruction is to stay by the wall because there is a downcurrent just beyond it. The dive exit instruction each time is to go up the wall and back away from the edge before ascending. The last time I was there, the current was so strong that there were divers who could not pull themselves away from the edge. Dive guides banged their tanks to get our attention and signaled ti let go and ascend through the downcurrent. It was fun but I was not unduly troubled thanks to the lift capacity of my wing.

 

[outofofficebrb]

And what did you folks do, after clinging to the wall? How did you folk get out of it?

We maintained contact with the wall with our muck sticks, while kicking upwards and off to another part of the wall where we hypothesized the current was not as strong based on the direction the fish were swimming in. It was not fun. Then the current changed directions and we hid in a corner and took turns going up. It was a wild dive. I sent you the video via WhatsApp just now.

 

[TabeaK]

As I mentioned in post #72 in this thread, Raja Ampat diver death, there won't be any current at the wall and you don't know how far (parameter d in Figure 4.7.1, below) and wide (lateral direction) the downcurrent is. My quick reaction is to swim to the wall as the current velocity would be lesser towards the wall and zero at the wall, as shown in Figure 4.7.1, below. You don't need to mess with your buoyancy, just find a way to hide/attach yourself to the wall.

I won't wander too far into the blue in places like this. So, swimming to the reef/wall would be quick, should be < 90-137 feet / minute descent.


View attachment 815736
Courtesy of John Southard, Massachusetts Institute of Technology, 4.7: Velocity Profiles

While I get this from a general physics perspective, I have been on walls in Socorro, where the downcurrent was absolutely strongest right at the wall. Strong incentive to keep 10-15 ft away from said wall. Definitely no 0 velocity when at the wall. Would not have dared to try and attach myself to said wall...

 

[DownUnderwater Dan]

While I get this from a general physics perspective, I have been on walls in Socorro, where the downcurrent was absolutely strongest right at the wall. Strong incentive to keep 10-15 ft away from said wall. Definitely no 0 velocity when at the wall. Would not have dared to try and attach myself to said wall...

The problem with trying to stay 10-15 ft away from a wall in an extreme downcurrent situation in Indonesia, is depending on the varied topography of the dive sites, means that you could face a number of other life or death situations.

1. You could encounter a whirlpool vortex, a literal washing machine, getting violently tossed around and also getting pushed down.

2. Often, some of the most spectacular dive sites in Indo, you can often have 2 or even 3 different seas/oceans meeting at precise location of dive site. Meaning you could get ripped away from wall structure area and fly off into the direction of potentially open sea, never to be seen or found again.

3. Being off the wall in extreme downcurrent means that you have absolutely nothing to hang onto, meaning that you would be using all your energy to stop from going down, and exhausting yourself to limit, and away from other divers on wall, no one can help/save you. Which would also create unnecessary risk and panic.

I've posted an example of a whirlpool in Indonesia.

 

[Dan]

While I get this from a general physics perspective, I have been on walls in Socorro, where the downcurrent was absolutely strongest right at the wall. Strong incentive to keep 10-15 ft away from said wall. Definitely no 0 velocity when at the wall. Would not have dared to try and attach myself to said wall...

I have never experienced such situation in Indonesia nor in Socorro. I have been to Socorro 3 times.

If that happens to me, I would go the opposite into the blue, where the current is lesser for obvious reason.

 

[CWK]

Swimming away from the wall to get away from a downcurrent can be interesting also.

Earlier in this thread I mentioned a dive at Manta Ridge when the current was so strong that some divers could not get away from the edge of the wall and guides signalled us to ascend through the downcurrent. As I went into the downcurrent I faced downcurrent to watch the bubbles and my log shows that I dropped from about 5m to about 15m before my BCD arrested my descent and pulled me up. Ahead of me I saw a dive guide holding on to a petite guest. They were about 5m in front and about 3m below me. They were in a whirlpool and were swinging around. I missed the whirlpool as my BCD had started to pull me out.

Imagine a shoebox. The narrow end is Manta Ridge. The current sweeps not just over the top but also along both sides. As the current sweeps over the top edge, it falls and creates the downcurrent, which in turn creates an area of low pressure just beyond the downcurrent. The current that sweeps along the sides of Manta Ridge gets pulled to the middle and forms a whirlpool. So you get a downcurrent and a whirlpool beyond that.

If you get a really long wall, you may not get the whirlpool beyond the downcurrent. It all depends on the topography of each site.

 

[DownUnderwater Dan]

Swimming away from the wall to get away from a downcurrent can be interesting also.

Earlier in this thread I mentioned a dive at Manta Ridge when the current was so strong that some divers could not get away from the edge of the wall and guides signalled us to ascend through the downcurrent. As I went into the downcurrent I faced downcurrent to watch the bubbles and my log shows that I dropped from about 5m to about 15m before my BCD arrested my descent and pulled me up. Ahead of me I saw a dive guide holding on to a petite guest. They were about 5m in front and about 3m below me. They were in a whirlpool and were swinging around. I missed the whirlpool as my BCD had started to pull me out.

Imagine a shoebox. The narrow end is Manta Ridge. The current sweeps not just over the top but also along both sides. As the current sweeps over the top edge, it falls and creates the downcurrent, which in turn creates an area of low pressure just beyond the downcurrent. The current that sweeps along the sides of Manta Ridge gets pulled to the middle and forms a whirlpool. So you get a downcurrent and a whirlpool beyond that.

If you get a really long wall, you may not get the whirlpool beyond the downcurrent. It all depends on the topography of each site.

In Komodo I got a double whammy of extreme downcurrent hanging onto a wall, to then getting thrown off the wall into a big whirlpool.

Dived Batu Bolong on a full moon, when the tide changed during the dive. The water turned really warm, and the thousands of big fish we were enjoying with, completely disappeared in the space of a few seconds, we knew instinctively something terrifying was about to happen.

Managed to hang onto wall, but fighting to keep reg and mask on, extreme downcurrent for 2 minutes till all the hard corals I was holding broke off and sent me flying/tumbling 10-15 metres off wall in an instant.

I was in a white water whirlpool, honestly couldn't tell my bearings due to water from every direction. I fully inflated BCD, was nearly drowning, ascent was super slow as was fighting whirlpool, I was down 15-20m and 10 minutes into dive. Made it to surface, my face was red and I was coughing, felt like I'd just been strangled for the last minute.

Staying on R4, I think like a lot of places in Indonesia, extreme situations can happen and it's unpredictable sometimes. But it shouldn't be a worrying factor, as extreme situations can happen anywhere in the world on a bad day.

This thread is raising awareness and useful info and tips for diving in these parts of the world

 

[CWK]

In Komodo I got a double whammy of extreme downcurrent hanging onto a wall, to then getting thrown off the wall into a big whirlpool.

Dived Batu Bolong on a full moon, when the tide changed during the dive. The water turned really warm, and the thousands of big fish we were enjoying with, completely disappeared in the space of a few seconds, we knew instinctively something terrifying was about to happen.

Managed to hang onto wall, but fighting to keep reg and mask on, extreme downcurrent for 2 minutes till all the hard corals I was holding broke off and sent me flying/tumbling 10-15 metres off wall in an instant.

I was in a white water whirlpool, honestly couldn't tell my bearings due to water from every direction. I fully inflated BCD, was nearly drowning, ascent was super slow as was fighting whirlpool, I was down 15-20m and 10 minutes into dive. Made it to surface, my face was red and I was coughing, felt like I'd just been strangled for the last minute.

Staying on R4, I think like a lot of places in Indonesia, extreme situations can happen and it's unpredictable sometimes. But it shouldn't be a worrying factor, as extreme situations can happen anywhere in the world on a bad day.

This thread is raising awareness and useful info and tips for diving in these parts of the world

I’ve dived both sides of Batu Bolong, one side on a rising tide and the other on a falling tide. One side is warm and the other is cold. Diving that site during a change of tide could be adventurous as you have found out.

 

[TabeaK]

The problem with trying to stay 10-15 ft away from a wall in an extreme downcurrent situation in Indonesia, is depending on the varied topography of the dive sites, means that you could face a number of other life or death situations.

1. You could encounter a whirlpool vortex, a literal washing machine, getting violently tossed around and also getting pushed down.

2. Often, some of the most spectacular dive sites in Indo, you can often have 2 or even 3 different seas/oceans meeting at precise location of dive site. Meaning you could get ripped away from wall structure area and fly off into the direction of potentially open sea, never to be seen or found again.

3. Being off the wall in extreme downcurrent means that you have absolutely nothing to hang onto, meaning that you would be using all your energy to stop from going down, and exhausting yourself to limit, and away from other divers on wall, no one can help/save you. Which would also create unnecessary risk and panic.

I've posted an example of a whirlpool in Indonesia.

Well, like said, this particular occurrence in Soccoro the downcurrent was worst on the wall. It doesn’t really have anything to do with the examples you posted.

Point is it depends on the circumstances.