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- Sailboat Guide
Zephyr is a 20 ′ 0 ″ / 6.1 m monohull sailboat designed by Ed Thrall & Jack Freitag and built by Basin Boatcraft/Invader Marine (USA) starting in 1949.
Rig and Sails
Auxilary power, accomodations, calculations.
The theoretical maximum speed that a displacement hull can move efficiently through the water is determined by it's waterline length and displacement. It may be unable to reach this speed if the boat is underpowered or heavily loaded, though it may exceed this speed given enough power. Read more.
Classic hull speed formula:
Hull Speed = 1.34 x √LWL
Max Speed/Length ratio = 8.26 ÷ Displacement/Length ratio .311 Hull Speed = Max Speed/Length ratio x √LWL
Sail Area / Displacement Ratio
A measure of the power of the sails relative to the weight of the boat. The higher the number, the higher the performance, but the harder the boat will be to handle. This ratio is a "non-dimensional" value that facilitates comparisons between boats of different types and sizes. Read more.
SA/D = SA ÷ (D ÷ 64) 2/3
- SA : Sail area in square feet, derived by adding the mainsail area to 100% of the foretriangle area (the lateral area above the deck between the mast and the forestay).
- D : Displacement in pounds.
Ballast / Displacement Ratio
A measure of the stability of a boat's hull that suggests how well a monohull will stand up to its sails. The ballast displacement ratio indicates how much of the weight of a boat is placed for maximum stability against capsizing and is an indicator of stiffness and resistance to capsize.
Ballast / Displacement * 100
Displacement / Length Ratio
A measure of the weight of the boat relative to it's length at the waterline. The higher a boat’s D/L ratio, the more easily it will carry a load and the more comfortable its motion will be. The lower a boat's ratio is, the less power it takes to drive the boat to its nominal hull speed or beyond. Read more.
D/L = (D ÷ 2240) ÷ (0.01 x LWL)³
- D: Displacement of the boat in pounds.
- LWL: Waterline length in feet
Comfort Ratio
This ratio assess how quickly and abruptly a boat’s hull reacts to waves in a significant seaway, these being the elements of a boat’s motion most likely to cause seasickness. Read more.
Comfort ratio = D ÷ (.65 x (.7 LWL + .3 LOA) x Beam 1.33 )
- D: Displacement of the boat in pounds
- LOA: Length overall in feet
- Beam: Width of boat at the widest point in feet
Capsize Screening Formula
This formula attempts to indicate whether a given boat might be too wide and light to readily right itself after being overturned in extreme conditions. Read more.
CSV = Beam ÷ ³√(D / 64)
Similar to the Hunt designed INTERNATIONAL 110. Raced as a one-design class for a number of years on San Francisco Bay.
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- SGM 6 April 2021
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- Yachting NZ 2021 - Zephyr Proves Popularity at Nationals
- Live Sail Die 2021 - Cameron Dunn's First Impression of the Zephyr
- Yachting NZ 2021 - 65th Nationals
- Sailworld 2021 - 70 Boats for Zephyr Nationals
- Yachting NZ 2020 - Picton Nationals
- Former America's Cup Sailor in Zephyr
- Boating New Zealand 2016 - 60th Anniversary
- Stuff - 60th Anniversary at Manly 2016
- Sailworld 2016 - Fibreglass Zephyr
- 2010 Nationals in Tauranga
- Stuff 2009 - Des Townson 1934 - 2009
- Sail World 2006 -50th Anniversary
- Classic Boat 2000 - Interview with Des Townson
- Sea Spray 2002 - Class Distinction
- Sea Spray - 1957
- Membership Form
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- In The Workshop
- Model Zephyr Hobby
- Boats For Sale on TradeMe
- Spars & Sails
- Beach Trolleys
- Book: 'Des Townson' by Brian Peet
- Zephyr Clothing
- Picton Nationals 2020 - Christel Hopkins
- Picton South Islands 2019 - Dan Mackay
- Picton South Islands 2019 - Christel Hopkins
- 2019 North Islands - Taupō
- Tauranga Nationals 2019 - Roger Whitefield
- 2019 Nationals - Tauranga
- Wellington Nationals -2018 - Irina Winsely
- CZOA - Andy Holland Series 2018 - Ron Finch
- 2018 Nationals - Wellington
- PCYC Spring Series 2018 - Luca Roccati
- 2017 Nationals - Akaroa
- Manly Nationals 2016 - 60th Anniversary
- Akaroa South Islands - 2016
- Pigeon Bay South Islands - 2015
- Lyttelton Nationals - 2014
- Manly Nationals - 2013
- 2011 Nationals - Akaroa
- Model Zephyrs by Chris Bridges
- Glass Zephyr
- 1957 Archive - History
- 1957 Archive - Des Townson
- 1957 Archive - Sea Spray Test
- 1957 Archive - Restoration
- Zephyr Class Rules
- YNZ Racing Rules
- Class Documents
- Measurement Certificates
- Mast and Hull Measurements
- ZOA Executive Committee
- Yachting New Zealand
2024 NATIONALS - LYTTELTON
59 Zephyrs spent Waitangi Weekend 2024 battling it out in on Lyttelton Harbour, with Mark "MarkO" Orams taking his second consecutive win! A big thanks to host club Naval Point Club Lyttelton, RO Phil Folter & team, the event's sponsors, and event photographer/media Suellen Hurling from LiveSailDie for helping promote our class to NZ sailors!
MEDIA COVERAGE FROM LIVE SAIL DIE
DAY THREE REPORT
Mark Orams builds a picket fence at the 67th Zephyr Nationals by LiveSailDie
READ ARTICLE
Congratulations to Mark “MarkO” Orams, our Zephyr National Champion of 2024!
The Sailing Professor had a few great words to share...
MARKO'S SPEECH
DAY ONE REPORT
59 Shades of Grey at the 67th Zephyr Nationals in Lyttelton by LiveSailDie
DAY TWO REPORT
"It was the best of times, it was the worst of times..." - by Live Sail Die
No ego and no protests at the 2023 Zephyr Nationals in Wellington by LiveSailDie
"@ZephyrYacht has better Nationals coverage than the Olympics classes!" - Jo Aleh, watching from Auckland
LIVE REPLAYS
Wondering if the Zephyr is for you? Want to know more about our boats?
LIVE SAIL DIE PRESENTS...
22 questions with zoa president, matt mitchell, about the zephyr class:.
FOLLOW ALONG!
2024 north island champs, taupo: 9-10 nov 2024.
Notice of Race see LTYC read more
2023 SOUTH ISLAND CHAMPS
The latest news.
Photo: Mike Drummond in Zephyr #606 "A-Z" match racing Emirates Team New Zealand in their winning boat "Te Rehutai" on her first sail! - Photo thanks to LiveSailDie
ZEPHYR NATIONALS 2021
The name sponsor of the 2021 Nationals, Salthouse Next Generation Boats, had a drone & camera out on the water during the regatta. Watch all the fun (and carnage) in their video!
Manly Sailing Club's commodore Barry Thom chats to ZOA President Matt Mitchell, Youth & Women sailor Penny Linton, and the National Champ of 2021 Rod Dawson.
A video from the start boat on Day Three of the Zephyr Nationals 2021. This was Day Two of racing due to the postponement on Saturday 10th April.
HIGH-QUALITY EVENT PHOTOS
Photos from the 2021 Zephyr Nationals in Auckland at Manly Sailing Club are available to purchase.
2,000+ high-quality photos available from Craig Butland Photography.
2024/2025 SEASON MEMBERSHIP
Subs are due for the new season.
Join the ZOA and your regional association or renew your membership
$55 membership, or $30 for Zephyr sailors under 25 years old.
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