I now believe that Float 48 is now in a stable state on the surface, sending ARGOS fixes and awaiting recovery. We should be able to recover it using the RDF, just like we did 47.

The float started showing file system errors earlier today. These progressed and after 10 write errors, it aborted the mission, blew the bolt (we think) and tried to start the recovery mode program. However, the program load didn't succeed probably because the file system is crashed leaving only the backup ARGOS location system.

The lessons are the usual ones:
There are a nearly infinite number of ways for things to go wrong
The ones that get you are the ones you didn't think of or assumed were fixed or some strange combination
The ones you know about and test for don't get you, so more testing is better.
A good backup system, Argos and the bolt, plus the watchdog and sensible recovery logic, often gets the vehicle back home.

We are pleased that these floats worked as well as they did. The float captured the growth and saturation of the bloom. This is the part that we believe will be most easy to understand. All the sensors except for one optode worked well and remained free of biofouling as far as we can tell, so we have redundant records of light, oxygen, optical biomass proxies and nitrate in a nearly Lagrangian framework for 50 days. We eagerly anticipate the data analysis.