What is the name of the device that consists of a padded weight attached to the end of a nylon shot line?

The device described in the question is known as a bolo. A bolo typically consists of a padded weight at one end that is connected to a nylon shot line. This configuration allows it to be thrown effectively, often for the purpose of retrieving lines or initiating a connection in a towing scenario. The weight helps to carry the line over distance and improve accuracy during deployments.

In contrast, a buoy serves as a floating marker that indicates underwater hazards or provides mooring assistance. A float generally refers to any object that is designed to remain on the surface of the water but lacks the specific construction that a bolo features. An anchor is a device used to secure a vessel to the seabed, preventing it from drifting but does not involve the line deployment characteristic of a bolo. Thus, the bolo is the correct term for the device described.