We discovered a stowaway in the car on our way out to the dive site. Everyone took that to be a good omen.

This was our last day in Mexico, so the flow meters were going in for their first long term installation today.  The over night run trials went smoothly so the last minute rebuild of logger 2 fixed the excessive power drain issue. (whew!)
But all the testing I had done over the last few days (with the units sampling and recording at a furious pace) meant that I had to scavenge the remaining good batteries out of our dive lights for the deployment.  I loaded the loggers with a sketch set to take readings every 30 minutes, and sealed the housings.

Then we loaded up our dive gear and drove to Playa de Carmen, to meet a reporter who had been interviewing Trish over the last few days. She was going to dive with us today to get video of us, and also of the little data loggers, for a documentary she was making about the growing water quality issues in the region.  Unfortunately she was was not a cave diver, so we did a “pretend” deployment on a large mangrove root out in the open water. Once she had captured the footage she needed, Trish and I continued on into the cave.

Because we were uncertain about the weight of the new batteries, we decided to install both units as pendulums for this deployment. The current at this location was pretty strong, so it was a bit challenging to stay in place, while affixing the “ceiling anchors” to the roof of the cave.

After securing the sensors, we did a final swim round to inspect the installation:

Fare well little sensor pods! We will come back in a few months to get you…we promise!

<—Click here to continue reading—>