Day 4: Area Scanning

Day 4 and the biggest lesson learned today was that salt water is extremely corrosive to electrical connections.

Today was the area scanning contest, the idea for area scanning is to scan an area and visit as many points on a grid as possible. The boat did well to begin with, the moment it was put in the water it headed for the course. But when you are out on the water watching the boat you don't see the actual course, there are some buoys which roughly mark part of the course. So it difficult to know if the boat is on course or not. After putting the boat in the water it did head in the right direction, but it just kept going. Eventually it was clear that it was heading off course and looking that the rudder, it was not moving. So we picked the boat out of the water and abandoned the contest, we did a 2nd attempt later.

Back on shore it was clear what had happened, somehow water had managed to get inside the boat, there was a good 1/2 cup of water in the boat. So the electronics were quickly taken out. We learned that even a little bit of salt water was very corrosive. The solder on some of the electrical components had significantly eroded. The best that could be done was to wash the components in tap water and dry them immediately.

Our area scanning attempt

Our area scanning attempt

The boat, a borrowed boat from ENSTA (the French team) had been modified, it had a big hole cut into the side, see image below. The purpose of the hole is to get access to be able to place electronics into it effectively. The hole also had a cable coming from the wind vane at the top of the mast. To cover the hole there was a tape that could be cut to cover it. Because the boat was slightly round and the tape flat it was difficult to perfectly seal the hole. But we used more tape around the edge of the tape to ensure the seal was better.

Hole in the hold

Hole in the hold

But this was obviously not good enough. After talking to the organiser, Jose, he also pointed out that when you put the boat in the water the water cools the boat and the air inside it, this causes a low pressure zone inside the boat and it will try to suck anything in to fill that area, air or water.

Our second attempt later in the afternoon was just the same, the boat took on water and had issues, only completing two squares again.