Dive Flags in Canada THE BOTTOM LINE

Sean Smyrichinsky   Aug 14, 2026

Dive Flags Canadian Dive Regulations Recreational Diving Diver Down Flag Alpha Flag Collision Regulations Scuba Diving Canada BC Diving Vancouver Island Diving Boat Diving Shore Diving Scuba Safety UB Diving

The Bottom Line About Dive Flags in Canada

First, Let's Kill the Distance Myth

We've all heard boats have to stay 100 feet, 200 feet or 50 metres away from a dive flag.

Nope.

Canada's Collision Regulations do not create a universal legal distance around a recreational dive flag.

No magic circle. Let's put that one to bed right now.

I'm talking about recreational diving only, based on Canada's current Collision Regulations. Commercial and occupational diving are another topic for another day.

Two Flags — Don't Mix Them Up

The red-and-white diver-down flag is the one most recreational divers recognize. It is red with a white diagonal stripe and is commonly used to mark an area where diving is taking place.

The Alpha flag is blue and white with a notch cut out of the end. It means: "I have a diver down; keep well clear at slow speed."

Canada's Collision Regulations do not tell a recreational dive vessel to fly the red-and-white diver-down flag. When the diving-vessel requirements of Rule 27 apply, they specifically name Alpha.

The two flags are not the same and they are not interchangeable.

Diving From Shore

Walking in from shore?

Canada's Collision Regulations do not generally require recreational shore divers to tow either flag.

Simple as that.

Diving From a Boat

Having recreational divers in the water does not automatically mean your boat has to display Alpha.

The key is whether the boat is restricted in its ability to manoeuvre because of the diving operation.

When Rule 27 applies and the vessel's size makes displaying the full signals impracticable, it calls for a rigid Alpha flag at least one metre high and visible all around. There are additional signals required as well.

Being under 12 metres does not automatically exempt a dive boat. In fact, Rule 27 specifically makes an exception for vessels engaged in diving operations.

Night diving from a boat also has lighting requirements. That's another topic.

The Bottom Line

No magic distance around a recreational dive flag under Canada's Collision Regulations.

Shore divers are not generally required by those regulations to tow a flag.

Red-and-white and Alpha are two different flags.

The Collision Regulations specifically name Alpha — not the red-and-white diver-down flag — for the diving-vessel situation covered by Rule 27.

That's the bottom line.

Be excellent,

Sean