Swapping Dive Computers
A diver had a regulator free-flow problem and decided to replace it with another of the same kind. Both had a dive computer attached. Should he use the new computer set up?
>After the third dive of the morning, a buddy team surfaced due to a second-stage free-flow failure. During the surface interval, I noted that the buddy team and several other divers were attempting to correct the problem. It was determined that the regulator had a mechanical failure that could not be corrected. A diver in the group offered the effected diver a spare regulator setup for use during the rest of the trip.
>Later I overheard a discussion about using the computer attached to the borrowed setup; someone said that "it is the same kind of computer so there is no problem with operation."
>I immediately advised them against using the new computer because it could not account for the previous two dives to 80-plus feet the diver had already made. None of the team members had thought of that problem because they were too focused on getting a functioning regulator setup for the effected diver.
>I suggested the diver use the computer from his previous dives; he did, and the group continued without any problems for the remainder of the dive trip. That diver avoided a possible episode of decompression sickness.
>This was good advice from the third diver. A dive computer is a personal device and is only as good as its record of all the diver's dives separated by surface intervals shorter than 24 hours.
>Divers should never start another dive on the same day using a different dive computer. Additionally, experienced and knowledgeable bystanders should not hesitate to provide proper advice; it may be lifesaving.
>To learn more, read "Your Computer Fails: Now What?" by Robert N. Rossier.
— Dr. Petar J. Denoble