Error What should I have done differently? Diving incident in Cozumel.

[Norwegian Cave Diver]

For me there are two different answers for two different level of divers.
If you are a new or newer diver then leaving is most like what you will do and what you should do.
For me and perhaps many others who are much more comfortable and experienced in the water and with deeper dives the answer could easily be different.
For the OP... it all worked out good. Wife was ok, DM was ok, you were ok, and the diver that went to see the sharks is ok, and he "apologized profusely".
I would only ask a couple questions of him... Did you check your air/gas remaining, and check your depth before making the decision to go see the sharks? If he did then he made a calculated decision, vs a random decision. I would expect the husband and wife are a team, and therefore the DM and the shark guy are a team. You could have motioned to the DM, "I will buddy up with my wife the ascend to the surface, you go with the shark guy." But that may not be how a new or newer diver would think.
The OP learnt from this, the shark guy learnt from this. All good for me.

 

[Shawn C]

Thanks for the feedback - it is appreciated.

When my wife and I debriefed the incident over some cervezas back at the resort, I came to the conclusion, which she absolutely agreed with, that I should not have left her. We were a buddy team (and she's rather important to me). I reasoned, in the moment, that she was OK by staying with DM as I knew she had 1200 psi and I still had around 1000 psi of gas left. I had plenty of deco space left but I wasn't going to descend regardless.

I think calling him an idiot is a little harsh. He wasn't the most experienced diver but he certainly wasn't new either. I did not see him check his gauges but he likely had already done so when the DM gave us the thumbs up as I had observed him checking his gas several times during the dive. He made a poor decision and I followed up by making a questionable one. We all ended up learning some important lessons that day and no one was hurt in the process.

Cheers.

 

[Norwegian Cave Diver]

For the OP...
I agree with everything you have said.
To give you a different perspective...
As a cave diver we train to very high standards. Zero visibility, lost line, lost diver, loss of gas (Sidemount) exiting with gas sharing, etc. We are not buddies but instead a TEAM. We think alike - the same as I would expect you and your wife do. We are there to help each other if there is an issue. The one who has an issue will always be in the lead as we exit - so there is always the team mate watching 100% of the time.
You cared about the other diver - unlike some of the other commentators on this tread. I don't know you, but I know enough about you to say, I would ocean dive with you and your wife. Cant say the same for the negative angry people.

 

[Still Kicking]

This reminds me a bit of a situation I found myself in a long time ago diving Vancouver Island. I got an instabuddy who was a French or French Canadian instructor. The boat dive briefing was to start the dive at slack and then drift with the current as the tide started running. We were in independent buddy teams with no DM in the water. The boat would follow us and be there to pick us up at the end of the dive. I had dove in Cozumel before and this was a familiar plan to me.

The first part of the dive went well but at about half gas, the instructor signaled that we should turn around and swim back toward our entry spot. I signaled no -- we should keep drifting. He was emphatic.

Being a relatively new diver back then -- trained to never leave a buddy and deferential to an instructor -- I complied and we struggled our way up current until we reached our surfacing pressure.

Of course, the boat was waiting for us and picking up the rest of the group a couple hundred yards down current and had to come pick us up. I wasn't a big deal in the end but I felt bad for breaking the plan and it was an up-current slog compared to the fun drift dive we should have enjoyed.

If I had been more experienced, I would have waved goodbye and continued with my dive according to the original plan. Looking back, I think it was probably one of the first times I thought to myself "I'd be better off solo."

 

[MidOH]

Frenchie didn't pay attention to the dive briefing.

It's kinda hard to miss "one way drift dive", and/or "follow the leader".

Aren't nearly all dives in CZM, drift dives?

 

[Norwegian Cave Diver]

This reminds me a bit of a situation I found myself in a long time ago diving Vancouver Island. I got an instabuddy who was a French or French Canadian instructor. The boat dive briefing was to start the dive at slack and then drift with the current as the tide started running. We were in independent buddy teams with no DM in the water. The boat would follow us and be there to pick us up at the end of the dive. I had dove in Cozumel before and this was a familiar plan to me.

The first part of the dive went well but at about half gas, the instructor signaled that we should turn around and swim back toward our entry spot. I signaled no -- we should keep drifting. He was emphatic.

Being a relatively new diver back then -- trained to never leave a buddy and deferential to an instructor -- I complied and we struggled our way up current until we reached our surfacing pressure.

Of course, the boat was waiting for us and picking up the rest of the group a couple hundred yards down current and had to come pick us up. I wasn't a big deal in the end but I felt bad for breaking the plan and it was an up-current slog compared to the fun drift dive we should have enjoyed.

If I had been more experienced, I would have waved goodbye and continued with my dive according to the original plan. Looking back, I think it was probably one of the first times I thought to myself "I'd be better off solo."

Sometimes you bring an asset with you on a dive, sometimes you bring a liability, and sometimes you don’t find that out until your in the water and the dive has begun.

 

[steinbil]

If I had been more experienced, I would have waved goodbye and continued with my dive according to the original plan.

I disagree with this sentiment. Of course, your buddy was in the wrong, and didn't pay attention to the dive briefing. But deciding to leave him would also have been wrong, as long as following him does not put you in danger. Two wrongs don't make a right. You would be right to be annoyed at him and refuse to be his buddy on a later dive. If it's really bad, then maybe even complain to the captain/dive leader, and hope for a refund or at least a better buddy next dive. But as a buddy you should strive to stick together, even when it's the less fun option.

 

[MidOH]

Wasn't his buddy. He spread out from his buddy to keep an eye on him.

 

[Pavao]

He'd never practiced shooting his SMB and when he tried to shoot it during his safety stop, he ending up losing it. There went his best chance and being spotted on the surface. He had no other signaling device.

Anything else that I can use as a lesson for the future?

This isn't on you, the guy made bad choices and you did the best you could to try and fix a problem that weren't really yours.

What I quoted I think is the biggest take away from this. Although the issues with the SMB weren't with you or your group, that can serve as a lesson to have spares, just to exemplify with one scenario, a reel could foul during deployment, there goes your SMB.
This isn't the first time someone did not have a SMB on the surface, even though the diver did have a SMB.
When you saw your boat disappearing in the horizon, I bet you wished (or glad) you had the biggest and brightest SMB, right?

Also have a comment on the practice there, do I understand this dive started as a drift dive and the DM was not carrying a dive float/flag? I don't wanna make much judgement here as I know nothing about the diving in the area, but drift diving without a flag would make me raise an eyebrow

 

[Shawn C]

This isn't on you, the guy made bad choices and you did the best you could to try and fix a problem that weren't really yours.

What I quoted I think is the biggest take away from this. Although the issues with the SMB weren't with you or your group, that can serve as a lesson to have spares, just to exemplify with one scenario, a reel could foul during deployment, there goes your SMB.
This isn't the first time someone did not have a SMB on the surface, even though the diver did have a SMB.
When you saw your boat disappearing in the horizon, I bet you wished (or glad) you had the biggest and brightest SMB, right?

Also have a comment on the practice there, do I understand this dive started as a drift dive and the DM was not carrying a dive float/flag? I don't wanna make much judgement here as I know nothing about the diving in the area, but drift diving without a flag would make me raise an eyebrow

Thanks for your thoughts. To answer your questions, when we drifted out of sight of the boat I was, indeed, very happy that I choose the 6' version of the SMBs. I also outfitted my wife with her own and in a different colour as I wasn't sure if orange or yellow works best (or if they work about the same?). We both also have whistles and I always carry a dive light.

Drift diving in Cozumel is not done with floats or flags. The captains know the reefs and current and are amazingly good at following the bubbles on the surface. Towards the end of the dive, the DM will shoot his SMB at depth as another marker for the captain (and other boats). Many people will stick with the DM and go up. My wife and are are decent on our consumption (her better than me) so we will sometimes continue the dive if there's still reef and gas available. Then we will ascend together using my SMB which I shoot at around 30', reel up to 15', safety stop, and then reel up to the surface checking for boats overhead as we go.