MacGyvering a sonar with a car battery

Did the power supply for your Simrad 710 sonar die? No problem, simply hook it up to a car battery. Apparently this is what happened during leg 1 of the cruise I am on. I boarded the R/V Pelican yesterday for a week long research cruise off the Florida panhandle, and the Simrad EM710 sonar's power supply was a simple car battery. We surveyed with this all day today, but are now back in port waiting for a FedEx delivery containing the new, proper, power supply. I must say, that was some impressive MacGyvering!