Snatch it to a track slide to make a genoa lead block. When changing headsails up or down, snatch blocks can carry the load temporarily while a new sheet is being rigged. Use it with a line tied to the boom as a preventer when sailing off the wind, or use a snatch block as a fairlead to lead an anchor line to a cockpit winch when kedging off after you've run aground. They can be used anywhere there is an attachment point, except as genoa turning blocks. While snatch blocks are very strong, they are not intended to carry the heavy loads from a genoa.
Some jobs call for trunnion snatch blocks.
These blocks swivel on two planes simultaneously to assure a fair lead. They're useful on spinnaker foreguys, vangs, preventers, sheets, and cunninghams, and are recommended where attachment to a toe rail is mandatory, or where the block cannot be suspended by its attachment becket to make it stand up when not loaded. Make sure that you allow for full articulation of deck or toerail-mounted snatch blocks. Usually it is best to attach a standard shackle to the toerail, and then attach the snatch block to this shackle, rather than attaching the snatch block directly to the toe rail. For safety, position the opening of the snatch block away from the load.