GONE are the days when the only surface marker buoy (SMB) reel available was the one you made yourself. Ready-made reels are now available in moulded or machined plastic. They tend to have a smooth action and a good locking mechanism, and are designed for easy use underwater. Prices can vary from around £15 to around £150 for stainless steel.
The SMB is towed by the diver, who must always be careful to keep the line wound in to avoid any risk of entanglement.
Cave divers need a variety of reels. These include main penetration reels loaded with very long lines, and smaller reels for spurring off a main guide line - or for emergency circular searches to retrieve a guide line should the diver become separated from it.
Technical divers have recently taken to using the smaller type of reels originally intended for cave divers. These are usually made from aluminium or stainless steel, with Lexan or Perspex drums. They rarely come equipped with a ratchet.
If you need to send a deployment SMB to the surface for use during stage decompression stops, these smaller reels can be very useful. However, you must be sure that the line does not jam during the buoy's ascent, or it might drag you up with it.