This marker float is a device used by anglers to measure and indicate the depth of water in a specific fishing spot. It is attached to a fishing line and cast to the desired location. A free weight is placed along the line to sink the setup to the bottom. Then, you simply release the line and wait for the float to rise to the surface, revealing the depth at that spot.

To better understand how it works, feel free to watch videos of existing marker floats, as mine operates in the same manner.

To attach the Marker Float to the line, I threaded fluorocarbon through the hole in the cap twice, added a split shot to prevent it from slipping out, and tied a simple knot at the exit of the cap.

I tested it by submerging it overnight at a depth of one meter and casting it into the water about a hundred times. There was no degradation and no water penetration.