Salish Sea Sentinels

Did you know that the presence of professional whale watch boats can help keep whales safe? The Salish Sea is a huge body of water, covering nearly 7,000 square miles. While law enforcement officers are on the water to enforce regulations as much as they can be, with limited resources and multiple groups of whales in the area at one time, it’s impossible to be everywhere at once. Professional whale watchers are the often the only line of defense when it comes to protecting local whales.

Sentinel Actions

Each year, PWWA operators document hundreds of sentinel actions. A sentinel action is an intervention performed by a PWWA crew member during a tour to help protect marine wildlife.

Examples of sentinel actions include:

• Stopping other vessels from speeding near whales

• Proactively warning vessels of whales nearby so they can slow down/alter course

• Removing harmful debris from the water

• Reporting sick or entangled animals to authorities

In 2025, PWWA operators were successful in positively influencing the behavior of other vessels following at least 72% of interventions. When necessary, we also document egregious violations of whale regulations and report them to local law enforcement agencies.

You can read more about the PWWA’s sentinel actions in our annual Sightings & Sentinel Actions Reports.

The Sentinel Effect

The boater education and monitoring group Soundwatch reports that more than 50% of recreational boaters are unaware of boating regulations around whales. PWWA operators are experienced professionals who help mark the location of the whales and warn others of their presence.

An independent peer-reviewed study found that the number of high-risk recreational boating incidents around killer whales in the Salish Sea is reduced by more than half when there are professional whale watch vessels in the area to help mark the location of whales and model appropriate speeds and distances.

Whale Warning Flag

The Whale Warning Flag was developed as a way to alert boaters of whales in the vicinity. First utilized by our colleagues with the North Island Marine Mammal Stewardship Association (NIMMSA) near north Vancouver Island, the flag was introduced to the lower Salish Sea in 2018 and is steadily gaining recognition.

Based on the concept of a “diver down” flag, the Whale Warning Flag indicates to nearby boaters that whales are within 1 kilometer of the vessel flying the flag. It’s best to slow down and use caution any time you see a whale watch vessel traveling slowly in an area, but the whale warning flag is a tool that can be used by any vessel, not just professional whale watchers, to communicate about the presence of whales.