The Vang-Master rigid pneumatic boom vang is now distributed by Harken as the Harken Vang-Master, so you get the same air-spring vang with faster availability and Harken-backed support. It replaces mechanical springs with air pressure to hold the boom up and keep optimal mainsail shape, and MAURIPRO Sailing stocks the full Harken Vang-Master range.
Harken Vang-Master at a glance
| Feature | Detail |
|---|---|
| Type | Rigid pneumatic (air-spring) boom vang — no mechanical springs |
| Function | Provides extension force to hold the boom up and hold mainsail shape |
| Material | 6061 T6 aluminum, hardcoat-anodized tubing and end fittings |
| Sizes | Vang-Master 1 through 8, across four cylinder diameters |
| Adjustment | Manual pump sets air pressure; squeak-free operation |
| Purchase systems | 4:1 or 6:1, single- or double-ended, 40 / 57 / 75 mm Carbo blocks |
| Fit reference | 120+ stock applications from Moore 24 to Andrews 70 |
What changed when Vang-Master became Harken Vang-Master?
For years sailors relied on the Vang-Master rigid pneumatic boom vang for its quality and simplicity. Harken has now entered an agreement to distribute the line as the Harken Vang-Master, which means better distribution, shorter delivery lead times, and Harken-backed technical support. The product itself is unchanged — an infinitely adjustable, turnkey solution for maintaining optimal mainsail shape. As one of the largest online Harken dealers, MAURIPRO Sailing carries every Harken Vang-Master boom vang and purchase system.
How does the Harken Vang-Master work?
Harken Vang-Masters use air pressure rather than a mechanical spring to provide the extension force that holds the boom up. You set the air pressure with a manual pump, which makes the vang infinitely adjustable and squeak-free. The body is built from 6061 T6 aluminum, so it is light and strong, and the tubing and end fittings are hardcoat-anodized to resist corrosion. The line comes in four cylinder diameters with a menu of more than 120 stock applications — from Moore 24s to Andrews 70s — that you match to your rig using pin-to-pin measurements. Stainless steel mast and boom fittings and custom lengths are also available.
Which purchase system should I choose?
An external purchase system built from Harken blocks gives you the mechanical advantage to trim the vang under load. Standard systems are offered for each Vang-Master size in 4:1 or 6:1 ratios and in single- or double-ended configurations. Smaller sizes (VM1–VM3) use 40 mm Carbo blocks and 6 mm line; mid sizes (VM4–VM6) use 57 mm blocks and 8 mm line; the largest (VM7–VM8) use 75 mm blocks and 10 mm line. Double-ended systems let you adjust from either side of the boat, which is handy for shorthanded and cruising crews.
How do I measure for the right Vang-Master size?
Before ordering, take two measurements. First, find your PCLC and PCLO (pin center length closed and pin center length open): measure the distance between the vang pins with the boom pulled fully down (closed), then push the boom up to the maximum desired height and measure between the pins again (open). Those two numbers point you to the correct Vang-Master size. Second, select the purchase system — 4:1 or 6:1 mechanical advantage in a single- or double-ended configuration — to suit your boat and sailing style.
Harken Vang-Master technical data
Purchase systems are pre-measured, spliced, and supplied with line selected for the application. Match the system to your Vang-Master size before ordering.
| Part No. | Description | Purchase | Use with |
|---|---|---|---|
| 7500 | 4:1 Single-ended 40 mm Carbo | 4:1 | VM1, VM2, VM3 |
| 7501 | 4:1 Double-ended 40 mm Carbo | 4:1 | VM1, VM2, VM3 |
| 7502 | 6:1 Single-ended 40 mm Carbo | 6:1 | VM1, VM2, VM3 |
| 7503 | 6:1 Double-ended 40 mm Carbo | 6:1 | VM1, VM2, VM3 |
| 7504 | 4:1 Single-ended 57 mm Carbo | 4:1 | VM4, VM5, VM6 |
| 7505 | 4:1 Double-ended 57 mm Carbo | 4:1 | VM4, VM5, VM6 |
| 7506 | 6:1 Single-ended 57 mm Carbo | 6:1 | VM4, VM5, VM6 |
| 7507 | 6:1 Double-ended 57 mm Carbo | 6:1 | VM4, VM5, VM6 |
| 7508 | 4:1 Single-ended 75 mm Carbo | 4:1 | VM7, VM8 |
| 7509 | 4:1 Double-ended 75 mm Carbo | 4:1 | VM7, VM8 |
| 7510 | 6:1 Single-ended 75 mm Carbo | 6:1 | VM7, VM8 |
| 7511 | 6:1 Double-ended 75 mm Carbo | 6:1 | VM7, VM8 |
Frequently asked questions
Is the Harken Vang-Master the same product as the old Vang-Master?
Yes. It is the same rigid pneumatic boom vang, now distributed by Harken with improved availability and technical support. The design, sizes, and purchase systems are unchanged.
How does a pneumatic boom vang hold the boom up?
It uses air pressure instead of a mechanical spring to provide extension force. You set the pressure with a manual pump, so the vang is infinitely adjustable and stays squeak-free.
What is the Vang-Master made of?
The body is 6061 T6 aluminum with hardcoat-anodized tubing and end fittings, making it light, strong, and corrosion-resistant.
What do PCLC and PCLO mean?
PCLC is pin center length closed (boom fully down) and PCLO is pin center length open (boom at maximum height). Measuring both between the vang pins tells you which Vang-Master size fits your boat.
Should I choose 4:1 or 6:1, single- or double-ended?
A 6:1 ratio gives more mechanical advantage for easier trimming under load, while double-ended systems let you adjust from either side of the cockpit. Choose based on your boat size and how your crew sails.
How do I know which size fits my boat?
Harken lists 120+ stock applications by production model — for example VM-2 for a J/24, VM-4 for a Catalina 34, or VM-6 for a Catalina 400. Confirm with your PCLC/PCLO pin-to-pin measurements, and our team can help verify the fit.