Vernon Runs Away

When the vehicle was dissembled to debug the connection issues yesterday one of the sonar molex connectors was broken. This meant despite going out again in the afternoon and running the mission scheduled for the morning, no sonar data was gathered. Today we planned to rerun that mission so we could collect the sonar data.

At the end of the rerun mission Vernon surface as normal and proceeded to drive to the parking point. We located him and began to drive towards him, but on the way their Vernon turned into our boat. Jason, the boat driver attempted to turn out of the way but could not see Vernon and ended up turning in the same direction as Vernon. Chris and I were standing at the bow of the boat and felt Vernon collide head on. A couple moments later it surfaced at the other side of the boat. Chris jumped in to inspect it and found nothing wrong. Its sensors seemed to be working and there was battery left to run two more lines so we loaded them up and pressed go.

At this point the deployment and monitoring of the AUV had lost its novelty and while driving over to the next surface point most of the ship's crew seemed rather tired and board of being stuck on the boat. During the first three lines everyone participated in sever games of hangman, but at this point no one was interested in playing anymore games. We arrived at the surface point a couple minutes ahead of when Vernon should have been there and began looking around for him. Usually he takes about 36 minutes to complete a leg so by the time 40 minutes had gone by we had gotten worried and when 48 minutes had gone by we decided something most have gone wrong.

Looking over the mission we had loaded I realized the safety settings said to abort the mission if it the depth to surface was more than 45.72 meters. Wentao looked over the depth charts and discover the first leg should have broke this depth limit in the first several meters. When a mission is aborted the Iver would normally surface and execute a safety return path, but no safety return path was included in this mission so we assumed it was probably just drifting in the current. Everyone was suddenly awakened from what had become a boring day and sent to the edge of the ship to look for Vernon as we back tacked our way along the surface of the last line. We were all looking for Vernon's yellow hull or white strobe light. The strobe was hard to spot because it was in the middle of the day so the most of the ocean's surface was constantly sparkling with sunlight. On the way back there were many false sightings of debris and ocean flashes, but no Vernon. Next we did a search assuming it surfaced soon after it had dives and had been carried by the current. Finding nothing, we returned to its final park point in case we had just missed it. Again it wasn't there, but as we left on another search a sail boat pulled along side and asked if we were looking for something.

It turns out the bump we had gave Vernon at the end of the previous mission, despite not physically damaging him, must have cut deep into his trust with us. At the beginning of the last mission his dive was merely a ruse. After ten minutes he surfaced looking for refuge and found a passing sail boat. After an hour or so he realized it was all a mistake and decided to come back.

Vernon's Temporary Refuge

Once we had Vernon safety back on our boat we looked over the log files and, as expected, a couple of minutes into the dive the depth limit was exceeded and he surfaced to be recovered by the passing sail boat.

(The Iver3 AUV is named Vernon.)