SMBs vs DSMBs: What's The Difference And What Do I Need?

An important safety item that you need to take on all dives is an SMB (surface marker buoy) or DSMB (delayed surface marker buoy). Both SMBs and DSMBs are safety buoys that are used for scuba diving. They fluorescent buoys that are deployed underwater, that shoot up to the surface once air has been blown into them and act as a signal to others on diver locations underwater.

SMBs and DSMBs are often brightly coloured with “diver down” flag, indicating that there are divers below. Both SMBs and DSMBs do the job of telling others on the surfaces your location underwater.

What are the similarities of SMBs and DSMBs?

In a nutshell, both SMBs and DSMBs do the exact same thing and are intended for the same purpose. They’re a safety item that lets people on the surface know where divers are located. But there are many differences between the two which is why you need to do your research to find the one that best suits your needs. Lucky for you, we’ve got all the answers here for you, so keep on reading to find out more!

What’s the Difference Between a SMB or DSMB?

So when it comes to selecting your gear, which one do you need so that it fits in with your diving needs? Here we’ll find out the difference between the two safety buoys so you can discover which one will work best for you based on their features, differences and uses.

SMB (Surface Marker Buoy)

SMBs vs DSMBs: What’s The Difference and What Do I Need? - Mike's Dive Store

SMBs towed for the whole dive and indicates the position of the dive group throughout the dive. SMBs are usually used in shallow coastal locations where there’s a high chance of boat traffic, so boats can constantly see your location and avoid passing overhead. Many divers also use SMBs during boat dives so the boat crew can keep tabs on your location at all times when you’re diving and can easily follow the divers if needed. The SMB is especially good for getting attention if lost at sea or if an accident happens.

DSMB (Delayed Surface Marker Buoy)

The one main factor in why some divers choose DSMBs is because DSMBs are deployed towards the end of the dive. The DSMB is deployed so that it signals to the surface that the divers have started to ascend. DSMBs lines are designed to be deployed at safety stops, so most lines measure five metres and up.

Many divers prefer this option as they don't have to hold the buoy throughout their whole dive, as it can be tucked away in a pocket or clipped onto a D-ring throughout your dive and used when needed. DSMBs are probably the most versatile option for divers.

Why Do You Need an SMB or DSMB?

Now you know what SMBs and DSMBs are and the difference between the two, why do we recommend that you take one when you’re diving? The simple answer being this, because it’s a vital safety item. Carrying an SMB keeps you safe in many ways and for many different reasons. As we’ve already pointed out, it allows others to know on the surface, especially boats, and know diver locations.

SMBs and DSMBs are very important when used in high currents and when doing a drift dive. This is so boats can find your location quickly when you end up in a completely different place from your entry point. Having a brightly covered SMB or DSMB means that boats can find you quicker when needed.