How do you maintain the ROV / underwater drone?
The underwater drone must always be rinsed well after use. After use in salt water, but also after use in fresh water. It is also advisable to keep the tether clean.
Also, do not store the ROV wet. This also prevents the ROV from drying up. Preferably let it dry for a day or two in a room at room temperature.
Also, make sure the battery is charged to 50% for battery life.
What can you do with an underwater drone if there is virtually no visibility?
The ROV / underwater drone is equipped with lights, but if the water is very turbid, they are of little use. The ROV sees as much as a human sees underwater, but there are tools for that.
Sonar is required to see in murky water. Please note that sonar image is very different from a normal video recording. A GPS / USBL positioning system also helps locate the ROV.