One Design · Keelboat
Mercury parts, rigging and specifications
Also known as: Mercury 18, Mercury One Design, Mercury Class Yacht, Nunes Mercury
The Mercury is a keelboat one-design class designed by Ernest Nunes, with a published length overall of 18 ft (5.49 m). MAURIPRO lists 12 parts for the Mercury below, grouped by system, with live prices and stock.
- Keelboat
- 12 parts
- 11 published figures
Your Mercury at MAURIPRO
What you can do on this page.
Shop Mercury by system
Mercury parts
Prices and stock are live from our catalogue.
Harken part numbers cross-checked against Harken's published one-design deck layout for the Mercury (checked 2026-11-04).
Mercury specifications
| Specification | Published figure | Source |
|---|---|---|
| Length overall (LOA) | Length: Overall 18 feet (5.49 m) | Mercury Class Yacht Racing Association - Constitution / Bylaws / Rules (Revised 8-8-26), Specifications Article III Hull, Section 1(a); matches Harken one-design deck layout page, Compiled from published sources (mercury-sail.com, ussailing.org, en.wikipedia.org) |
| Waterline length (LWL)Approximate | Water Line: 13 feet (approximately) (3.96 m) | MCYRA Constitution / Bylaws / Rules (Revised 8-8-26), Article III Section 1(c) |
| Beam | Beam 5 feet 4 inches | MCYRA Constitution / Bylaws / Rules (Revised 8-8-26), Article III Section 1(b); matches Harken one-design deck layout page, Compiled from published sources (mercury-sail.com, ussailing.org, en.wikipedia.org) |
| DraftApproximate | Draft: 3 feet 1 inch (approximately) | MCYRA Constitution / Bylaws / Rules (Revised 8-8-26), Article III Section 1(d) |
| Hull weightClass minimum, less spars and loose gear | 1,100 lb (499 kg) | MCYRA Constitution / Bylaws / Rules (Revised 8-8-26), Article III Section 1(e) |
| Hull weightClass minimum, weighed with mast, without boom and loose gear | 1,125 lb (510 kg) | MCYRA Constitution / Bylaws / Rules (Revised 8-8-26), Article III Section 1(e) |
| BallastClass maximum lead keel incl | The weight of the keel together with the bolts, washers and nuts shall not exceed 635 pounds. (288 kg) | MCYRA Constitution / Bylaws / Rules (Revised 8-8-26), Specifications Section 8 Lead keel (b) |
| Sail area (as published, total) | 167 sq ft (15.5 m²)Other published figure: 200 sq ft (18.5 sq m) (Harken one-design deck layout page) | Compiled from published sources (mercury-sail.com, ussailing.org, en.wikipedia.org) |
| Mast lengthClass maximum, deck to masthead | The height from the deck to the top of the mast shall not exceed 24 feet 6 inches. (21 Jan 06) | MCYRA Constitution / Bylaws / Rules (Revised 8-8-26), Spars Section 1 Mast (b) |
| Crew | A yacht shall be raced with a crew of no more than two persons | MCYRA Constitution / Bylaws / Rules (Revised 8-8-26), Racing rules Section 3 Crew |
| Designer | Ernest Nunes, 1939 (class and US Sailing profile) | Compiled from published sources (mercury-sail.com, ussailing.org, en.wikipedia.org) |
Figures are shown as each source publishes them, with the other unit converted. Class rules set the measurements that count for racing.
Mercury tuning guides
- Mercury Class Yacht Racing Association (MCYRA): Mercury Class Tuning Guide (Don Whelan and Doug Baird set-ups)Version 1998 · 4 pages
Tuning guides belong to the sailmakers that publish them. MAURIPRO does not host or reproduce them; ask the sailmaker or your class association for a copy.
Mercury class rules and references
- Class rules: MCYRA Constitution / Bylaws / Rules incl. Measurement Specifications, revised 8-8-26 (Aug 2026)
- Class association: mercury-sail.com
References checked 2026-11-04.
Mercury buying questions
What Mercury parts does MAURIPRO carry?
12 products are listed for the Mercury on this page: blocks & sheaves (7); cleats, clutches & fairleads (3); travelers, tracks & cars (1); other parts (1). Prices and availability shown are live from our catalogue.
How do I know a part fits my Mercury?
Each part here is linked to the Mercury because its exact manufacturer part number appears on the Mercury parts lists we reviewed (including Harken's published one-design deck layout for this class). Fit can still depend on your boat's year, builder and rig, so check the product details and your class rules, or ask our technical team before you order.
Are there tuning guides for the Mercury?
Sailmakers have published tuning guides for this class, including Mercury Class Yacht Racing Association (MCYRA) (Mercury Class Tuning Guide (Don Whelan and Doug Baird set-ups), Undated web page (MCYRA site, copyright 1998–2026); PDF copy on US Sailing created July 2021 (5 pages)). These guides belong to their publishers; MAURIPRO does not host or reproduce them, so please get them from the sailmaker or your class association.
Which rules govern the Mercury?
The class is governed by its class rules (MCYRA Constitution / Bylaws / Rules incl. Measurement Specifications, revised 8-8-26 (Aug 2026)). Check the current edition with the class association before buying parts for racing.
Everything in this collection
All products currently in this MAURIPRO collection, with filters.
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Harken Cam Cleat - Carbo-Cam (Micro) 471 - Line: 1/8 to 1/4 in (3 to 6 mm)
HAR471
$32.95 USDUnit price /Unavailable -
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Harken Line-Shedding Endstops - For Travelers: 1/2 in (13.0 mm) Micro - Low-Beam (Pair)
HAR2706
$10.95 USDUnit price /Unavailable -
Harken Block - Carbo Ratchamatic 57mm Single - Cheek - Standard Grip (Black)
HAR2633
$128.95 USDUnit price /Unavailable -
Harken Block - Carbo Ratchamatic 57mm Single - Swivel / Standard Grip (Black)
HAR2625
$125.95 USDUnit price /Unavailable -
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Harken Swivel Cam Cleat - Base (Small) w/ Cam-Matic 150 - Line: 1/4 to 5/8 in (6 to 16 mm)
HAR205
$168.95 USDUnit price /Unavailable -
Harken Cam Cleat - Cam-Matic 150 - Line: 1/8 to 1/2 in (3 to 12 mm)
HAR150
$45.95 USDUnit price /Unavailable
