Dive Essentials

What to look for in dive essentials

Frequently asked questions

What is the difference between an SMB and DSMB?

An SMB (Surface Marker Buoy) is a brightly coloured buoy used to mark a diver's location at the surface, making it easier for boats and shore support to spot divers. A DSMB (Delayed Surface Marker Buoy) is deployed underwater and rises to the surface while the diver remains below. DSMBs are commonly used during safety stops, drift dives, and boat dives to signal a diver's position before surfacing. Both improve diver visibility and safety, but a DSMB is specifically designed to be deployed during the dive rather than only at the surface. DSMBs typically have an open-bottom or self-sealing inflation system, an over-pressure relief valve, and an attachment point for a reel or spool. An SMB (Surface Marker Buoy) is generally inflated and used at the surface, often featuring a simpler design without a pressure-relief valve or specialized underwater deployment features. DSMBs are commonly taller and more streamlined to remain visible in waves and current, making them the preferred choice for drift diving, boat diving, and safety stops.

What type of dive slate should I buy?

For recreational diving, the three-page white slate is the most versatile — three panels give you room for a dive plan, a site map, and running notes all on one slate. For night diving or low-visibility dives, the glow-in-the-dark slate is both a writing surface and a visual reference in the dark. All slates come with a pencil and wrist strap. Pencils write reliably underwater on a slate surface; pens do not. Erase the slate with a wetsuit or cloth after the dive. For technical divers doing decompression, a wrist-mounted slate large enough to write a deco schedule is more practical than a pocket slate.

What is the diver down flag and the alpha flag?

The Diver Down flag is a red flag with a white diagonal stripe used primarily in Canada, the United States, and some other regions to indicate that divers are in the water nearby. Boats should stay clear of the area and proceed with caution. The Alpha flag is an international maritime signal flag that is white and blue. It indicates that a vessel has divers in the water and is restricted in its ability to maneuver. The Alpha flag is recognized worldwide and is often required by law when diving from a boat in many countries. In general, the Diver Down flag is a diver-specific warning marker, while the Alpha flag is an internationally recognized signal used by vessels to communicate the presence of divers. Many dive boats display both flags to maximize visibility and comply with local regulations.

How do I deploy a surface marker buoy?

The standard method: at the end of your dive while still at your safety stop depth (5 metres), unclip your SMB and reel from your BCD pocket. Hold the bottom of the SMB open and exhale a small breath of air into it to partially inflate it. The air expands as it rises, fully inflating the SMB at the surface. Let the reel spin freely as the SMB ascends — do not grip the reel tightly or you will be pulled up with it. Once the SMB is at the surface, maintain slight tension on the reel line and complete your safety stop. Ascend along the line at a controlled rate. Practice this skill in a pool or shallow confined water before your first open-water deployment. Don't have the reel clipped to you or your gear while it is deployed in case it becomes tangled at the surface and may drag or pull you unexpectedly.