Why is it important to have a surface marker buoy (SMB) during EANx dives?

Using a surface marker buoy (SMB) during EANx dives is important primarily because it indicates the diver's position at the surface during ascent. This becomes especially critical in situations where visibility is limited, either due to adverse weather conditions or when there are other boats or watercraft in the vicinity. An SMB signals to boat operators and other divers the location of the diver ascending, enhancing safety by reducing the risk of a diver being accidentally struck or causing an incident.

Furthermore, deploying an SMB helps maintain a direct line of ascent, which is crucial when diving with enriched air, as it helps divers avoid rapid ascents that could lead to decompression sickness. By clearly marking the diver's position, an SMB contributes not only to the safety of the diver but also promotes awareness of the dive site activity for everyone else in the area.