What is the largest type of reel used by divers?

The largest type of reel used by divers is the exploration reel. Exploration reels are specifically designed to hold a significant amount of line, which is crucial for deep or extended dives, particularly in cavern or cave environments. These reels can accommodate longer distances and provide the necessary safety for navigational purposes in complicated underwater landscapes.

The design of an exploration reel allows divers to lay out longer lines while ensuring they have enough material to return safely, which is a critical aspect of cavern diving. These reels often feature a larger spool to handle the increased length of line, along with sturdy construction to survive the rigors of diving conditions.

In contrast, standard reels, compact reels, and finger spools are generally smaller and meant for shorter distances or specific uses. While they have their place in diving, especially for tasks like marking a location or shorter penetrations, they do not offer the same capacity or versatility as exploration reels. This distinction highlights the importance of selecting the right type of reel based on the dive plan and environment.