swimthroughs and inherent danger thereof

[Taipeidiver]

Whether a particular swimthrough is an overhead environment can be tough to gauge; factors such as the availability of ambient light, depth, width and length all need to be considered and, ultimately, it is the decision of the DM and (especially) the individual diver which will determine whether a swimthrough is attempted.

We all need to dive within the limits of our experience, training and equipment. If you want to dive a long simwthrough / cave / wreck or other overhead environment then that's no problem, but do it right and survive.

 

[simonk999]

I don't agree that whether a swimthrough is an overhead environment or not is gauged by length, breadth, depth or light conditions. If you can't directly ascend to the surface, it is by definition an overhead environment. Certainly a very short swimthrough has only a short section where it is truly overhead, but when you're under solid rock/coral, you're under it, not just underwater.

Indeed, one ideally should only optionally go through a swimthrough; however, with follow-the-leader dives, one often does not have that option (i.e. without guide, could be difficult to find where group exits, or guide goes through expecting others to follow, etc). Not only that, but one often has no idea about the length, breadth, light conditions of a swimthrough before swimming through, i.e. first time through.

Just gotta be cognizant of the situation you're putting yourself in, I agree. Especially if you know that no others in your party are using long hoses!

-Simon

 

[Taipeidiver]

I agree with the definition of overhead environments given by Simon. Any location where you cannot ascend directly to the surface is, by definition, an overhead environment.

That said, I have dived swimthroughs which are very short and wide (like a broad archway), with plenty of light, which probably wouldn't be considered an overhead.

The point at which such parameters become overhead conditions is not defined and there is probably quite a variety of conditions to be considered. It is the individual diver that has to look at the conditions and decide if their equipment, training and experience is up to the requirements, as it is on any dive.

DMs / dive guides are also failing in their duty of care if they take groups down on dives for which they are not trained and equipped for.

 

[MikeFerrara]

A while back...a couple of years maybe, PADI came out and said that swim throughs were ok during recreational classes and that it was up to the instructor what a swim through was. Maybe they gave some general guid lines but I don't remember. I always had the feeling they did that because of all the resorts that do the swim throughs or duck into a wreck or whatever. I've heard of lots of close calls, groups leaving the lighted zone in a wreck when the only one with a light was the DM and all kinds of crazy stuff. I love diving caves more than any other diving I've ever done but I don't want to be anywhere around when one of these resorts drags a bunch of non-overhead trained folks through a coral cave or into a wreck.

 

[Michael Freeman]

Last time I was in a long swim through I got to meet a giant green eel that was at least 10+ inches in diameter. I knew he was coming from the girl screeming in her reg behind me. I looked back to see what the problem was and saw the biggest eel I have ever seen ( I didn't even know they could get even close to that size.) Since I was blocking its way, I moved over as far as I could as it just went by... and went by, and continued to go by. Very cool experience. Then on my way out a turtle spent some time swiming around in front of me. All and all one of my best Cozumel dives out of multiple trips.

Yes it was an overhead, yes the danger level was increased, but I believe it was worth the extra risk. I also race my sport bike (on the track) so my idea of risk my be a different scale then some.

 

[Sideband]

Indeed, one ideally should only optionally go through a swimthrough; however, with follow-the-leader dives, one often does not have that option (i.e. without guide, could be difficult to find where group exits, or guide goes through expecting others to follow, etc). Not only that, but one often has no idea about the length, breadth, light conditions of a swimthrough before swimming through, i.e. first time through.
-Simon

If I don't know all of that info I'm not doing the dive. If I can't turn around any time I feel like it, I'm not doing the swim through/dive. If there will be people blocking my path out at any time, I'm not doing the dive. If I can't see daylight from both ends at all times, I'm not doing the dive. I could go on. Looks like I'm not going to be doing many swim throughs. At least most of those discussed.
It took me probably 20 dives before I got up the nerve to enter a boat in our local quarry. 32' cabin cruiser, all windows and doors removed.

Joe

 

[Wijbrandus]

My wife and I flat out don't do swim-throughs anymore.

While we aren't trained in overhead environments, that's not the reason. We've already seen in our limited experience how much damage people do to the reefs and disturbances they create with the wildlife. I'm certainly not the best diver in the world, but I've got enough sense not to go somewhere where I can bounce off both the ceiling and the floor in the same five foot space.

We've also seen some complete yo-yos tearing up their rental gear on the coral. After nearly having my mask broken in the traffic jam as everyone tried to pack through at once, we decided to simply go over rather than through. Haven't looked back since.

Ain't nothin in a hole worth getting hurt over.

 

[RP Diver]

I personally evaluate a swimthrough before I enter and decide if the situation is worth it or not. I rarely do it if I'm in a group larger than 6 divers, and sometimes not then. I despise follow-the-leader diving, and if the group is doing the tunnel, I usually go elswhere, or just follow over the top of the reef and meet them at the exit point. If the depth and conditions are right, I may go back and do it later in the dive. If it's so tight that there is a significant risk of bouncing off the walls or ceiling, I probably won't do it. I agree that some swimthroughs qualify as overhead environments, and should be approached as such.

But I do love the feeling of going through a hole starting at 45 feet with a sand bottom and exiting into blue water at 90+ through a sheer wall of coral like some of the dives at Bloody Bay and Jackson's Walls on Little Cayman. There are some beautiful swimthroughs at Bus Stop and Randy's Gazebo, among others.

Typically, there is little risk of damage to the reef inside of a swimthrough, because the tunnel is already dead, whether naturally or from years of divers doing the same thing. IMO, most care needs to be taken on entrance and exit because that is where you are most likely to find live coral and sponges.

 

[Michael Freeman]

Didn't grab the quote, read next message

 

[Michael Freeman]

My wife and I flat out don't do swim-throughs anymore.

While we aren't trained in overhead environments, that's not the reason. We've already seen in our limited experience how much damage people do to the reefs and disturbances they create with the wildlife. I'm certainly not the best diver in the world, but I've got enough sense not to go somewhere where I can bounce off both the ceiling and the floor in the same five foot space.

We've also seen some complete yo-yos tearing up their rental gear on the coral. After nearly having my mask broken in the traffic jam as everyone tried to pack through at once, we decided to simply go over rather than through. Haven't looked back since.

Ain't nothin in a hole worth getting hurt over.

I agree, if you don't have enough control to maintain a set depth without bumping your way through, you don't belong in a tunnel. Save for the eel swimming by I touched nothing. I did turn on my side and set down in the sand to give him room to get past me, but no noticable amount of sand was "whipped up". but i set down very gently and floated back up without moving anything but my BCD inflator.

Eel didn't seem too concerned about us punny humans, and actually swam between the girls legs (i.e., the screaming girl). If he had a problem with us, he could have easily removed one of my arms for a light snack.