Today I had my second lagoon dive to run through the rest of the basic diving procedures. The simulated air failure (by turning off the tank) wasn't nearly as scary as I thought it would be on account of the relatively slow way the residual air between first and second stage gets used up. About the most distracting manoeuvre was full removal of the mask as while wearing contacts I had to close my eyes for the full minute. However re-attaching the mask went without any hitches.
I also did a number of buoyancy control exercises and worked on improving my breathing. Together with a smaller BCD, more comfortable fins and eventually less weights (about the only 2kg I can claim to have lost on the holiday) I proved to be a lot more adept at moving about in the sub-marine environment than yesterday. My instructor, apparently their most experienced, was certainly happy about my progress after our one-on-one session.
The only downside was that as we descended further I again experienced problems with re-equalising my ears. We only made it to about 1.5m before deciding to give up and head back to the pontoon. A follow-up to the on-site nurse confirmed my left ear has an inflamed section just outside the ear drum. Whether this is a pre-existing symptom or a result of the dives so far has yet to be determined. I shall see the doctor later on today. Either way the advice is to lay off the diving for a few days and re-check the ear before trying again. One advantage of the length of the trip is having that luxury.
UPDATE: Doctor says ear canals very inflamed and two have two days off and turn off the room A/C before coming back.