Nautilus Lifeline Work In Coz?

[NDL_Diver]

Don't overlook the obvious - one of the BEST ways to make sure the boat doesn't forget you is to make friendly conversation with the captain and the DM on the way out, and then have a large SMB inflated if you surface away from the boat. Knowing a few words in spanish doesn't hurt either. It's hard to forget someone who makes a good impression. Bonus points for starting a juicy story just before the dive and leaving them hanging until you get back.

Also dive with small group size helps. We dive six pac boats and missing a diver or 2 is obvious. Diving a boat with 16 or 20 people and one less diver can happen.
We carry a SMB, mirror and flashlight. On really remote or sites in North Cozumel I carry my Nautilus Radio ver 1 that has a full marine radio. They don't make them anymore and I just had it serviced.

 

[Nemrod]

The PLBs and such are certainly useful kit and yes a few divers over the years have had problems turning up missing. But, most of the regular dive sites are popular and there are boats all over. I have been asked upon surfacing away from my group due, to the DM having to tend newer divers and giving me the thumbs up to continue, asked by several boats where I belong and once was picked up and taken back to my boat during SI.

If you stay with your guide or in sight of them and also importantly carry a standard size DSMB and deploy it if separated there will be boats all over you trying to pick you up if you are far from yours (say the captain had an issue with another group). Most likely, about 96% of the time, with your DM or not, as soon as your head pops up you will see your captain headed to you or is already there. Getting left to sea in Cozumel, really is less likely than a meteor hitting you on your head during happy hour after dive.

 

[Dan]

I have been on several liveaboards that provide (free loan) Nautilus Lifeline or similar Personal AIS Beacon (PAB, not PLB) to the divers or DMs to make sure they could launch MOB if they were lost at sea:
Amira (Raja Ampat & Forgotten Islands)
Argo / Undersea Hunter (Cocos)
Ferox (Malpelo)
Galapagos Master
Infiniti (Visayas & Tubbataha)
Maldives Aggresor II
Mermaid I & II (Raja Ampat & Komodo)
Nautilus Undersea (Socorro)
Nautilus Belle Amie (Socorro)
Palau Aggressor
Red Sea Aggressor I
Rock Island Aggressor (Palau)
Spoilsport (Great Barrier Reefs)

I carry one to the liveaboards that don’t issue PAB to divers (Blue Manta & White Manta for example) and test it before cruising to see if MOB signal pops up on their AIS monitors and sounds the alarms when the red button is pressed.

 

[ggunn]

I have been on several liveaboards that provide (free loan) Nautilus Lifeline or similar Personal AIS Beacon (PAB, not PLB) to the divers or DMs to make sure they could launch MOB if they were lost at sea:
Amira (Raja Ampat & Forgotten Islands)
Argo / Undersea Hunter (Cocos)
Ferox (Malpelo)
Galapagos Master
Infiniti (Visayas & Tubbataha)
Maldives Aggresor II
Mermaid I & II (Raja Ampat & Komodo)
Nautilus Undersea (Socorro)
Nautilus Belle Amie (Socorro)
Palau Aggressor
Red Sea Aggressor I
Rock Island Aggressor (Palau)
Spoilsport (Great Barrier Reefs)

I carry one to the liveaboards that don’t issue PAB to divers (Blue Manta & White Manta for example) and test it before cruising to see if MOB signal pops up on their AIS monitors when the red button is pressed.

That's great and a lot more necessary for a liveaboard in the open sea.