|The Hobo datalogger shows how dark it is at the bottom of the lake next to the dock. The ROV made to excursions to the bottom.|
|It takes tine for the datalogger to cool down. U estimate there is a five degree difference in the surface and bottom temperatures, based on the timing indicated by the intensity chart.|
The second ascent to the surface took several minutes longer than the first because the ROV got stuck at the bottom. Something down there, a piling perhaps trapped the ROV. I was concerned the ROV tether would break and the ROV would remain at the bottom. Fortunately, the cat 5 tether was stronger. However, several thrusters were ripped from the ROV's wet frame.
I didn't discover what trapped the ROV, but I did discover the bottom of Lake Lowell is sandy near the dock.