I was with a group in Cancun for the week and we went over on Sunday to Coz. to dive. The Dive op was Deep Blue. I have a ToxiRAE3 CO sensor. I have not calibrated recently, but it is about 1 year old and is stored in an air tight container in a wine cellar when not in use to prolong the sensor life.
That said, the sensor "warmed up" and read 0 just as expected. I filled the first bag with air from the first tank and it slowly climbed to 12ppm. I tested every other tank on the boat and had readings of 0. Re-tested and still had the same reading.
FWIW, 10ppm is the max allowable, so 12ppm is probably not deadly. It was unusual to have a single tank with a higher reading.
The dive boat had a couple extra tanks and the guide was not defensive at all about it. He was happy to set the tank aside and put a rope around the valve to mark it so no-one would use it. I also personally kept track of the number on it so no-one used it.
I want to be very clear that I was pleased with Deep Blue's service. The rental equipment that my friends used was in good condition and I had a computer issue before the dive and they even had a couple spare computers onboard. The dives were good, and they did a great job of making it easy for us to come over from PDC to Coz for an afternoon dive trip. They also had spare tanks, which some trips I've been on would not have had extras available on the boat. I would recomend them and dive with them again.
I believe almost all ops in coz. get air from a central filling station, so it could just have easily been any other dive shop.
I understand that, in large part due to a scubaboard member, Cozumel air stations are monitoring C0. I'm posting this just to suggest that if you have a C0 sensor, it's still worth taking along.
That said, the sensor "warmed up" and read 0 just as expected. I filled the first bag with air from the first tank and it slowly climbed to 12ppm. I tested every other tank on the boat and had readings of 0. Re-tested and still had the same reading.
FWIW, 10ppm is the max allowable, so 12ppm is probably not deadly. It was unusual to have a single tank with a higher reading.
The dive boat had a couple extra tanks and the guide was not defensive at all about it. He was happy to set the tank aside and put a rope around the valve to mark it so no-one would use it. I also personally kept track of the number on it so no-one used it.
I want to be very clear that I was pleased with Deep Blue's service. The rental equipment that my friends used was in good condition and I had a computer issue before the dive and they even had a couple spare computers onboard. The dives were good, and they did a great job of making it easy for us to come over from PDC to Coz for an afternoon dive trip. They also had spare tanks, which some trips I've been on would not have had extras available on the boat. I would recomend them and dive with them again.
I believe almost all ops in coz. get air from a central filling station, so it could just have easily been any other dive shop.
I understand that, in large part due to a scubaboard member, Cozumel air stations are monitoring C0. I'm posting this just to suggest that if you have a C0 sensor, it's still worth taking along.