Screws turning with divers down

I recently did a Gulf of Mexico platform dive with some friends in a private boat. The boat owner is a very experienced diver (25+ years) and was solo spearfishing. I, my dive buddy, and a non-diver were waiting in the boat for the owner to surface, when the boat drifted near the platform.

The non-diver was at the boat controls. To pull the boat away from the platform, he cranked the engines and engaged the props. I told him not to turn the screws with a diver down, but he continued. I repeated my demand that he stop the screws 10 times, and he continued. I did not try to physically stop him, assuming that a physical altercation was more risky than moving the boat using the screws.

Am I too anal about this? Sure we can see the bubbles if a diver is not under duress when he approaches the boat, but what if he's OOA? I told the boat owner about all this, and he shrugged it off.

Was the boat in imminent danger?

"Drifted near the platform", as in... could have been fended off with gaffs?

Then no- not much reason to start the screws.

If it was dead calm, one diver down and you could track the bubbles? Maybe so. If you had to.

There are any number of reasons other than OOA that a diver can come up inadvertently under a boat.

I would set ground rules before going diving with your friends again. On a charter- ask the Captain what his take on it is.

The seas were less than 1'. The boat could have easily been fended off with a gaff.

You need to work on your "command" voice.



Bob
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I may be old, but I’m not dead yet.

We had a DISCUSSION about this in the context of a student diver who did a rapid and fatal ascent into the propeller of the boat she was diving from. Live boat diving is the norm in many places, and the boat does not always have the luxury of not engaging its propellers for the duration of the dives. It drops the divers as close to the reef as possible and frequently has to maneuver to pick those divers up and avoid the reef. On a typical charter boat, waiting until all the divers have surfaced might leave some divers bobbing for quite a while (or force people to end dives with a lot of leftover gas), which has its own attendant risks.

What we were in general agreement on was that some sort of propeller guard or shroud is a great solution. When I dived the Palau Agressor, for example, its skiff (and the mother vessel too, if I'm not mistaken) had thrusters, rather than an exposed propeller.

Yes it happens... If the boat is in danger its advisable to save everyone's ride home.

On the boat I normally dive if she breaks anchor they have to start over and drop them again. This meas moving boat and anchors entering the water and is covered in the briefing.

Props should not be in motion when recovering divers but repositioning is pretty normal.. no?

Of course people are going to operate their boat (turning screws) when divers are in the water! It is standard operating procedure in drift diving.

It is one of the MAJOR hazards of diving and everyone has to be careful.

The boat operator should be looking for bubbles, moving the boat slowly and should have a good idea where he thinks the divers are.

The concern about a diver ascending with no visible bubbles and coming under a live boat is a significant concern. This brings up one of the major safety rules about live boating that I hardly ever hear discussed. .....


DO NO swim or move horizontally in the water column at a shallow depth when the capt. may be operating the boat! If you are ascending and swimming horizontally, your are NOT under your bubbles. The captain will likely not know where you are and may even be deceived by assuming you are under your bubbles.

It is easy to see how and why people would do this.. they are comming up, they see the boat on the surface and they think it will be easy to swim 10-20 feet horizontally over to the boat as they ascend. They figure they will pop up right next to the boat and for some reason new divers are under the false impression that if they can see the boat, then the boat operator must be able to see them and does know that they are very close.

With a live boat, ascend under your bubbles. It is best to send up an smb on a string first, but not everyone does this every time. Another easy trick is to purge your reg for a few moments prior to ascending the last 8-10 feet. This should make a very visibile bubble plume that an attentive operator should be able to detect unless it is super rough or he is running too fast.

Having been on both side of this as both charter captain and diver it is sometimes necessary.
Rig diving has it's own particular problems in that wind and current can change direction requiring the boat to be repositioned during the time divers are in the water.
Also it is not uncommon for a supply boat to arrive at the rig when divers are in the water and they will not wait until all divers are out of the water. I have watched turning 6' propellers on supply boats while under the rig. They will back up against the rig and keep the propellers in reverse to hold the boat in place and can create a suction current.

Having been rig diving in the gulf quite a bit, I don't think it's really that big of a deal. Currents and winds can change pretty often out there, so holding a fairly large boat off a rig with a gaff is not giving much room for error. Divers (usually) ascend inside the rig structures then follow a rope out to the boat, rather than ascending directly under or to the boat anyway. Dive boats are generally held by winds 25-50' (or more) away from the rig.

The rigs I've been on are 20-26 miles out IIRC...that's a long swim, so you have to weigh the situation out. Can you see the divers and their bubbles? How fast is the boat approaching the rig? It's a pretty dynamic situation, and a generic "no screws with divers down" is unrealistic.