Navigating the Lanes: The Patos Island Race and Appendix TS

Picture this: You're racing through the darkness on a 67-nautical-mile offshore course. The wind is building. The current is ripping. And suddenly, the AIS alarm goes off: a massive container ship is bearing down on your position.

Welcome to the Patos Island Race.

Racing Through Maritime Highways

The Patos Island Race is the 43rd annual offshore regatta hosted by Sidney North Saanich Yacht Club. Scheduled for March 21-22, 2026, this 24-hour challenge opens the Vancouver Island Racing Series and takes competitors through some of the most tactically demanding and traffic-heavy waters in the Pacific Northwest.

The course runs through Haro Strait and Boundary Pass. These aren't just beautiful sailing grounds. They're active commercial shipping lanes with designated Traffic Separation Schemes.

That's where things get interesting.

What's a Traffic Separation Scheme?

Traffic Separation Schemes (TSS) are essentially maritime highways. Just like interstate freeways have northbound and southbound lanes separated by a median, TSS lanes keep commercial traffic organized and moving safely in opposite directions.

Haro Strait and Boundary Pass form a critical shipping corridor connecting the Strait of Juan de Fuca to the Strait of Georgia. Massive container ships, tankers, and cruise vessels transit these lanes daily, moving at speeds that make them difficult to maneuver or stop quickly.

The International Maritime Organization establishes these schemes. And the legal “rules of the road” that matter here are the Collision Regulations (COLREGs), specifically Rule 10.

What is a traffic lane?

If you’re in the scheme, the baseline expectation is simple: go with the flow. These guidelines are really the law.  Regardless of what the Racing Rules say, the Collision Regulations have the final say.  We've excerpted from the COLREG (Rule 10) that governs how to act around a TSS:

Rule 10(b)(i) says: “A vessel using a traffic separation scheme shall proceed in the appropriate traffic lane in the general direction of traffic flow for that lane.”

If you need to get across, the law is also pretty blunt about how to do it.

Rule 10(c) says: “A vessel shall, so far as practicable, avoid crossing traffic lanes but if obliged to do so shall cross on a heading as nearly as practicable at right angles to the general direction of traffic flow.”

All of that matters for racing because it’s not optional. It’s legal requirement first, tactics second.

Enter Appendix TS

The Racing Rules of Sailing recognized that yacht races and commercial shipping sometimes occupy the same water. Appendix TS (Version 4.0) provides the framework for how race committees and competitors handle these interactions.

Here's the core principle: Racing sailboats do not get any special privileges within a TSS.

Read that again. When you're racing through Haro Strait, you're subject to the International Regulations for Preventing Collisions at Sea (COLREGS): the same rules that govern all vessels. Your racing rules take a back seat to keeping everyone safe. More importantly, by using Appendix TS the Organizing Authorities can ensure accountability and some degree of control of how the racing fleet interacts with shipping. 

Appendix TS gives race committees specific tools to do this. There are three rules that a Race Committee can invoke in their Notice of Race (NoR). The invoked rule then governs how boats interact, cross, or avoid TSS lanes. Whichever rule is invoked (TS1, TS2, TS3 in Section A, B or C) will set the tone for how boats interact with shipping.

It may not be mentioned in the NoR, but it's vital to know what channel shipping is using within the lanes.  VHF calls are often your first indication that a merchant ship is coming your way.

How Appendix TS Works

The Patos Island Race course navigates multiple TSS crossings. Competitors round marks at Beaumont Shoals, Kelp Reef, and Patos Island itself, requiring strategic decisions about when and where to cross the traffic lanes.

TS1 (Section A) does two important things. It reinforces the COLREG rule about not impeding traffic in the TSS.  The next thing it does is set the threshold for accountability.  That is, it specifies when boats will be protested and what to do with complaints from shipping and the maritime authorities.   

TS2 (Section B) makes the TSS an obstruction. This means that boats are effectively barred from being in the TSS or presenting a threat of impeding shipping in the TSS.

TS3 (Section C) is a compromise between the first two and outlines how a boat is to operate within the TSS to ensure it presents the least chance of impeding shipping using the TSS.

The Tactical Challenge

Here's where it gets interesting from a racing perspective. Crossing a TSS isn't just about safety. It's tactical.

The currents in Haro Strait and Boundary Pass can run very strong. Timing your sailing in the TSS to ride favorable current while avoiding commercial traffic requires serious planning—and foresight. It's not just about you. If five sailboats are all proceeding up the lane, no one boat is impeding the merchant ship, but together they all are. If the commercial traffic is required to maneuver significantly, then all boats may be seen as impeding.

A boat that has been becalmed and drifted into the lane can be impeding. A visual lookout, plus AIS and VHF monitoring, is essential. Know the names of major landmarks and be ready to talk on the VHF to let shipping know what you're doing—early. 

Race Committee Responsibilities

Appendix TS also defines what the race committee must do. They're responsible for coordinating with maritime authorities before the race. They monitor traffic during the race by VHF, race tracker, and AIS-based shipping websites.

Appendix TS will explain what the Race Committee will do in terms of protest and thresholds for how boats that are racing will be held accountable for impeding commercial traffic.  If there are investigations or requests from traffic authorities, the Race Committee will participate and support those efforts.

This achieves two things. It ensures that those who take efforts to race responsibly are supported and hold accountable those who do not. Just as importantly, it shows the commercial traffic and traffic services that racers take safety and shipping seriously, which helps to ensure that the racing community is respected and continues to have access to the amazing racecourses that races like Patos provide.

Practical Tips for Racing Through TSS

If you're planning to race Patos Island or any other course that crosses TSS lanes, here's what you need to know:

Study the sailing instructions carefully. The race committee will specify exactly what's required under Appendix TS. Don't skim this section. Some races will provide opportunities to use your engine to avoid commercial traffic with minimal penalty. Know the SI.

Make sure your AIS is working. Most modern chartplotters display AIS targets. Use it. Set collision alarms. Pay attention to CPA (closest point of approach) and TCPA (time to closest point of approach) data.

Brief your crew. Everyone on deck needs to understand TSS protocol. Assign specific lookout responsibilities, especially at night.

Know the Area. Look at the course, the current predictions, and the typical traffic patterns. Have a strategy before you start.

When in doubt, stay clear. If you're not sure whether that container ship sees you, assume it doesn't. Give way early and decisively.

The Bigger Picture

Appendix TS reflects a fundamental truth about yacht racing: We share the water with commercial vessels that have limited maneuverability, tight schedules, and serious momentum. A massive container ship doing 20 knots needs over two miles to stop.

Racing through Haro Strait and Boundary Pass is an incredible experience. The scenery is spectacular. The tactical challenges are legitimate. And the competition is fierce.

But it all depends on everyone following the rules: both racing rules and rules of the road.

The Patos Island Race tests your boat handling, your tactics, your crew work, and your ability to race safely in challenging conditions. Understanding Appendix TS isn't just about compliance. It's about being a competent coastal racer.

Race Day Reality

When you're out there racing at 0200 hours, fighting three knots of adverse current in Boundary Pass, and the AIS shows a cruise ship inbound from Victoria, Appendix TS stops being an abstract concept. It becomes real.

That's when you appreciate the framework. You know what you're required to do. You know what the race committee expects. And you know that everyone on the course is operating under the same rules.

The 43rd annual Patos Island Race will test all of this. Sidney North Saanich Yacht Club runs an exceptional event with comprehensive safety protocols. They understand TSS management because they run races through these waters every season. Continued access to these racing areas depends on the good relations and safe sailing of competitors.

If you're racing Patos Island this year, read Appendix TS. Study the TSS charts for Haro Strait and Boundary Pass. Understand where the lanes are, which direction traffic flows, and where your crossing points will be.

Then get out there and race smart.

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Disclaimer: The safety information and advice shared in this article are for general guidance and information only. Every skipper and vessel operator is solely and ultimately responsible for the safety of their crew, boat, and decisions made on the water. All skippers must ensure they are fully informed, exercise their own judgment, and comply with all applicable laws, regulations, and race rules. Readers should do their own research and consult with qualified professionals as needed, as situations on the water can vary widely and may require different actions.