What do you do when the anchor line breaks free?

[PBcatfish]

In the instance I was involved in (as a diver, not captain or crew), a big chunk of the tie-in point broke off the ship from a combination of corrosion and metal fatigue. The whole thing was encrusted in marine growth, making any real inspection about impossible. The chunk that came off was maybe 3' x 5' big and had been attached to the rest or the wreck in three or four places.

Perhaps the lesson to be learned here is that if you are going to tie off to a wreck like that, it may be best to tie in anchor points for the up line at 3 or 4 different places & when one of them breaks, add a new tie in point to someplace else.

 

[TrimixToo]

Perhaps the lesson to be learned here is that if you are going to tie off to a wreck like that, it may be best to tie in anchor points for the up line at 3 or 4 different places & when one of them breaks, add a new tie in point to someplace else.

Maybe. Or testing the tie once in a while by putting it under tension with a winch or the boat's engines. But honestly, I have only seen this happen once, and it was a non-event. Everyone (or every team) just blew a bag and did their deco. As they came up the boat came and got them. Nobody got very far from the boat. The worst part of it was retrieving my strobe from the ball of stuff on the bottom.

 

[Gareth J]

It is interesting to see the different dive practices in different parts of the world.

In the UK it is exceptionally rare for the boat to moor into the shot line, almost unheard of.

Once at the wreck site the common practice is to shot the wreck (very few wrecks have a permanent shot on them - some popular sites like those in Scapa Flow, or around Plymouth etc may well have a shot attached).
Most shots are either a grapple, or a heavy weight.

The dive boat will then keep station near the shot, with a lookout looking for DSMB's whilst divers are in the water.

When the site is slack enough, the first pair will drop in, taking care to put minimal load on the shot. Often, they will then either hook the shot into the wreck, or use a waster line to tie the shot into the wreck.
In most cases, the last pair down ensures the shot is unhooked and free to be recovered by the boat (once all divers are out of the water), occasionally a lift bag is used to help recover heavy shots.

IF, the plan is for all divers to ascend the shot, then it will not be released by the last pair of divers on the descent.
An awful lot of UK dives do not be plan for the divers to return to the shot. The plan being that the divers will releasing a DSMB and ascending as they reach the end of their planned bottom time, drifting free of the wreck as they ascend/decompress.

On sites where an ascent is planned via the shot. There will often be a TAG in / out system. Tag in near the bottom on the way down, out as you start to ascend. If you are the last pair up you will remove the last TAG, indicating you are to ensure the shot is clear (possibly inflating the lift bag on the shot as well).
IF there was no shot when you returned for your ascent, then you would release a DSMB. You would NOT tie a DSMB in at the bottom, but ascend reeling in or spooling in the line as you go. (Tying a line in would in all likelyhood result in the DSMB being dragged back down to the seabed by the tide.)
(I have actually ascended a shot, only to meet the two buoy's at 15m because there is so much tide running they are being dragged back to the seabed - Leopoldville, Cherbourg.)

The dive boat will be keeping station near the shot, looking for DSMB's, and divers on the shot.
If you have ascended the shot, once the boat has acknowledged you, you release the shot and float downstream so that the boat can pick you up clear of the shot (and any divers).

In most cases, both divers will be expected to carry their own DSMB, and be capable of launching it solo, just in case they are separated. On a lot of boats, if there isn't one DSMB between a pair you wouldn't be allowed to dive. A lot of divers carry multiple DSMB's.

 

[crofrog]

It is interesting to see the different dive practices in different parts of the world.

NJ divers in typical NJ fashion do it there way and think any other way is horrible.

 

[doctormike]

NJ divers in typical NJ fashion do it there way and think any other way is horrible.

No we don't. We just assume that there is no other way.

 

[Nick_Radov]

Scootering on a wreck dive always seemed crazy to me, unless you were using it (Apollo, Mako style) to dig a hole for artifacts.

For some of our offshore dives the current is strong enough that I wouldn't even make it down the line without a scooter.

 

[Nick_Radov]

Wreck diving in the NYC area has a well established culture, with protocols and gear optimized over decades for this environment, at the cost of many tragedies and near misses.

Just because a culture is established doesn't mean that that it's the right approach. The protocols and equipment you describe appear to be — in mathematical terms — a "local maximum" rather than anything really optimal. You can change the culture if you want to.

We dive in deep cold water with often limited visibility. We dive in shipping lanes where heavy commercial traffic is frequent. And we may be diving on days with heavy seas, strong currents, or fog. Unlike locations where divers drift to and from the dive site and the boats follow them above, the boats here are tied into the wreck with a heavy rope and chain (the anchor line). They will have limited maneuverability, especially if there are divers in the water on long deco.

This is exactly why we no longer do deco dives from anchored or tied-in boats if there is any measurable current. The dive teams need to be on synchronized schedules and start their ascent roughly together under SMBs or some sort of floating grapnel rig. The boat stays live the entire time, following the divers while flying the Alfa flag and warning off other vessel traffic. For shipping lanes they might also have to do some advance planning with the Coast Guard or other local authorities. I've heard all sorts of excuses before about why that can't work in New York, which is obviously wrong because it works everywhere else in the world that it's been tried for 30+ years. There's nothing special about NY.

And if it's too foggy to see the SMBs then forget it, not worth the risk for sport diving. Wait until the fog clears or find another dive site. Don't put yourself in a situation where any single problem could kill you.

 

[Celt]

Just because a culture is established doesn't mean that that it's the right approach. The protocols and equipment you describe appear to be — in mathematical terms — a "local maximum" rather than anything really optimal. You can change the culture if you want to.

This is exactly why we no longer do deco dives from anchored or tied-in boats if there is any measurable current. The dive teams need to be on synchronized schedules and start their ascent roughly together under SMBs or some sort of floating grapnel rig. The boat stays live the entire time, following the divers while flying the Alfa flag and warning off other vessel traffic. For shipping lanes they might also have to do some advance planning with the Coast Guard or other local authorities. I've heard all sorts of excuses before about why that can't work in New York, which is obviously wrong because it works everywhere else in the world that it's been tried for 30+ years. There's nothing special about NY.

And if it's too foggy to see the SMBs then forget it, not worth the risk for sport diving. Wait until the fog clears or find another dive site. Don't put yourself in a situation where any single problem could kill you.

It would be nice to have perfect seas and weather with the whole place to yourself but that’s not the real world for some. Large ships can’t just move out of the way. Pair trawlers and beamers will pull right up to a wreck, gill netters will shoot a mile of net down on your little cosy spot. A fog bank doesn’t care if you have a line of divers on SMBs. Dive boats will want to be paid whether you decide to dive or not. We all don’t live in your perfect world. We have to make a living and deal with the conditions we live in. Some don’t have the luxury of saying ahh sure it’ll be flat calm without a cloud or another person in sight next week and we can dive then. I can see the skippers face when I tell him I don’t think we should dive today I can see a fishing boat.

 

[rjack321]

There's nothing special about NY.

Actually NY and NJ harbors are kinda special in that there's a giant continental shelf offshore with all the wrecks on it. And its outside the vessel traffic lanes (VTS). West Coast wrecks are generally within the VTS. So in NY and NJ large vessels are on their own navigation wise and yes you can get run down. In comparison for instance, inside of the Channel Islands to Long Beach CA, the entirety of Puget Sound and the Salish Sea from Comox BC south are all under the direction of the US and Canadian Coast guards and ships have to follow established lanes and get authorized to start, stop, enter, and leave those lanes. You can't just dive in those lanes and if you do get permission to dive there they will route traffic around you for the duration of your dive.

 

[Nick_Radov]

It would be nice to have perfect seas and weather with the whole place to yourself but that’s not the real world for some.

Sure, the seas and weather in the northeast Pacific Ocean are always "perfect". It's a tropical paradise here and the huge fleet of fishing boats never visits our dive sites.

A fog bank doesn’t care if you have a line of divers on SMBs.

Fog banks can be seen on the weather satellite imagery. If fog is an issue then wait for it to clear or dive somewhere else.
The notion of boat diving in fog is just insane. One minor mistake and even without a deco obligation a diver could easily surface out of sight of the boat crew. Then what?

Dive boats will want to be paid whether you decide to dive or not.

Sometimes we end up paying for a boat ride and don't get to actually dive. Luck of the draw. People trying to "get their money's worth" leads to all sorts of preventable problems in an activity that, for most of us, is just a hobby. Enjoy the boat ride and take pictures of whales or something. Be sure to tip the crew.