Our opinion (Brian Allen):
I personally have had one in my kit bag for nearly 10 years, and love it. The Buddy SMB accompanied me diving across 4 continents and completed 100s of dives from 84m through to shallow reef dives. Having tried pretty much every SMB out there I have picked this one to use as it is simple, completely reliable, long lasting, and while being large enough to be seen easily even in really rough weather, it's also small enough to fit in my drysuit pocket (and wetsuit pocket for that matter, but not many people have those).The SMB is generally inflated using a regulator in the open bottom end. The gas passes through a slight constriction which forms the seal, and then remains in the buoy until you chose do deflate it. It also has an eyelet on the top that I often use to attach a glow stick if night diving, or a note if ever I needed to. This SMB is strongly recommended.
From AP Valves:
The BUDDY SMBC (Surface Marker Buoy Closed) is inflated by simply purging a second stage in the open end when underwater. The really clever bit is in the mouth where our unique self-sealing baffle - or duckbill valve - is forced shut, forming an airtight seal, on inflation.
The SMBC also features a stream-lining flap which folds back over the mouth and prevents any sea-anchor drag effect when used in a current.
The SMBC can be used as a delayed-action SMB or it can be inflated at the start of the dive and towed as a standard surface marker.
At the surface, the SMBC is pulled upright by tension on the line and clearly marks the diver's position. The baffle prevents air spillage and the buoy remains inflated making it easy for the surface crew to track the diver or for the diver to hold aloft and wave if separated from the boat.
A message slate, ID marker or reflector can be tied to the top eyelet.
For more information please have a look at the Ap Valves website
Dimensions: 1.4m long x 20cm wide
Available in Red, Yellow or Red&Yellow