These Halcyon Diver Alert Markers are open bottom surface marker buoys, which are used to signal your position on the surface. SMBs are essential safety equipment every diver should carry. Due to their bright colours, orange or yellow, they are highly visible. With 1.4m (4.5ft) length, the SMB is well visible from a distance.
You can store them in the Halcyon Storage Pak or the Halcyon Bellows Pocket.