Velocity Made Good

Unlocking VMG: More Than Just Boat Speed

In sailing, Velocity Made Good (VMG) refers to the component of a sailboat’s speed that is directed directly toward or away from the wind—or, more precisely, how effectively the boat is actually progressing toward a windward or leeward mark. It’s not simply about the boat’s raw speed through the water—it’s about how that speed translates into forward progress toward your goal.

Why VMG Matters in Racing

In fleet racing, especially on upwind or downwind legs, VMG is the key to victory. The boat that consistently posts the highest average VMG typically wins SailZing.comLake Tahoe Sailing. Even if you’re physically slower, if you’re heading in a direction that keeps you gaining ground fastest, you’ll reach the mark before faster—but poorly aimed—boats.

Balancing Speed and Angle

Here lies the essential trade-off: sailing straight at the mark might seem logical, but you’ll be sacrificing speed. On the other hand, sailing at a broader angle might let you go faster—but too broad, and you’ll be going sideways instead of forward.

Here’s how VMG helps:

  • VMG is calculated as the boat speed multiplied by the cosine of the angle between your actual heading and the direction of the wind or mark mandurahyachtacademy.auoceansail.co.uk.
  • For example, you might sail at 5 knots at 55°, yielding one VMG, but at 5.2 knots at 65°, your VMG could be lower or higher depending on the angle. It’s all about maximizing that forward component WikipediaHandWiki.

Thus, finding the sweet spot—where moderate heading offsets yield significant speed gains—is the art of VMG.

VMG vs. VMC: Know the Difference

These two acronyms often get mixed up, so here’s how they differ:

  • VMG (Velocity Made Good): The component of speed relative to the wind direction—upwind or downwind WikipediaNauticEd Sailing Blog.
  • VMC (Velocity Made Good on Course): The component of speed toward a specific waypoint or mark, regardless of wind direction. This is what many GPS devices actually calculate Wikipediastarpath.com.

Understanding which one your instruments are showing—and what you want to optimize—is critical to sailing well MM Sailingstarpath.com.

How Sailors “Chase” VMG

Optimizing VMG is all about crewing your angle and trim. Here’s how sailors typically approach it:

  • Use Target Boat Speeds: Many racing sailboats have polar speed charts that tell you how fast you can go at different headings and wind speeds. Matching your actual speed to these “target speeds” helps maximize VMG SailZing.com.
  • Watch for Shifts, Gusts, and Currents: VMG isn’t static. Wind shifts, puffs, and current changes all affect ideal angles. Crews adjust heading or trim to keep VMG high—even if for just a few seconds Toplevel SailingLake Tahoe Sailing.
  • Keep It Averages, Not Instant: Instantaneous VMG readings can be erratic—watch the average over time to assess true progress ashtree-marine.comSailZing.com.

Bringing It Back to Lake St. Clair Sailing School

At Lake St. Clair Sailing School, we want every student to learn sailing that’s not just about going fast, but about going smart. VMG embodies that concept: it’s speed with purpose, precision, and purpose.

Encourage your students to:

  • Learn how to read their instruments—are they seeing VMG or VMC?
  • Practice angle adjustments to feel what gives better progress toward a mark.
  • Use target speeds and polar charts as guides, then validate with feedback from the boat and their instruments.

References