Please select your home edition
Edition
upffront 2018 Ronstan shock blocks Leaderboard

Reefing Your Mainsail: Are you onboard with reef hooks?

by Kerri Robson 4 Sep 08:00 UTC
Karver Reef Hook KHR © Karver

Founded in 2004, Karver set themselves the goal of developing and manufacturing hardware for the latest generation of high-tech yachts... and they are succeeding with just that.

From cam cleats to the recently acquired Karverized Pontos winches Karver have a plethora of high-performance hardware and furling solutions.

An ingenious addition to their portfolio, Karver's KHR Reef Hook offers an unconventional way to reef your mainsail.

Originally designed for ocean racing multihulls, reef hooks are now being adopted by more and more cruising sailors, who are choosing to replace their current pennant reefing system with a hook.

So, how does it work?

A reef hook is installed close to the boom's axis with a lashing. A small diameter control line guides the hook to the mainsail reef point, where a sheathed, high load Dyneema strop is sewn into the sail. This control line is used to draw the sail loop to the hook where it automatically locks into place.

On the boom, another release line is used to unhook the KHR. Both lines can be operated remotely - from the cockpit or mast step.

To activate the Karver KHR reef hook, simply haul down on the mainsail to get the reef point close to the hook. Pull the hooking control line to guide the hook inside the Dyneema strop and haul the mainsail back up again.

To unhook the Karver KHR reef lock, again ease down on the mainsail - whilst pulling the release line to get the hook out of the loop, and then haul up the mainsail again.

Each reef point on the main sail should have its own hook; it is advisable to rig each hook with a tight lashing or to protect it with neoprene to prevent impact on the boom.

But what are the benefits of a reef hook?

There are lots of benefits that make a reef hook more advantageous than a traditional pennant reefing system:

  • No line stretch - Textiles stretch under load. In a pennant system, line stretch is unavoidable and contributes to a loss of performance. A reefing hook avoids this, ensuring mainsail shape is stable and maintained.
  • Weight saving on the boom - The remote command lines used to activate or release the hook can be smaller in diameter as they only need to operate the hook. As a result, say goodbye to big, high load reefing lines and high load jammers.
  • No chafe - Reef lines will no longer chafe or break; lines are no longer permanently under tension in the jaws of jammers.
  • Reliable -There are no moving parts, so no need to worry about mechanical failure.
  • Reduces compression load - A Karver Reef Hook reduces the compression load in the boom.

In addition, sailors that have sailed with the Karver Reef Hook have stated that its simplicity and high performance make it an efficient reefing system with provides complete satisfaction out at sea, never letting a reef drop out.

The Karver Reef Hook is available in various sizes, with options available with 1T - 40T SWL (Safe Working Load).

To install the KHR, the position of the hooks on the boom must but be properly calculated, as the position of the hook must match up with the E-measurement (the distance from the aft-face of the mast to the reef clew point). If this is not done correctly, the outhaul or foot of the sail cannot be adjusted without the use of a hydraulic ram. The placement of the hooks can be fine-tuned after the first time at sea, in order to find the optimal position.

Want to make the move to a Karver Reef Hook? Explore the Karver Reef Hook range or for further advice contact us using this form.

Related Articles

What is a top down adapter?
A tack swivel is a popular evolution of the top-down furling system The top-down adapter, also known as a tack swivel, is an increasingly popular evolution of the top-down furling system. This technique provides cruisers and racers alike, simplicity, safety and speed for the handling of loose luff sails. Posted on 12 Sep
Transform your sailing with a Velocitek Speedpuck
Lightweight, compact speedometer with high accuracy Speedpuck is a responsive, digital speedometer which utilises the same GPS technology as the America's Cup-endorsed Prostart. Although suitable for boats of all sizes, the Speedpuck is known to particularly flourish on dinghies and one-design keelboats. Posted on 29 Aug
Karver's new 3:1 Friction Sheave
An increase in quality with a reduction in both weight and price It's not often that developments in fitting design deliver a significant increase in quality and a reduction in both weight and price - all at the same time. But Karver Systems appears to have achieved the impossible with the new 3:1 Friction Sheave. Posted on 21 Aug
Bjarne Lorenzen interviewed: Furling Your Mainsail
Andy Rice looks at 'in boom' and 'in mast' furling Most of the time we think of furling headsails but as Bjarne Lorenzen of sailmaker Doyle O'leu explains, there are options for mainsails too. In the fifth and final post from this series, Bjarne considers the pros and cons of 'in boom' or 'in mast'. Posted on 7 Aug
Ino-Rope update
The latest in textile block performance In light of the newly updated Ino-Rope product range, we ask you to cast your mind back to 2013: a French duo - experienced offshore Mini Transat 650 sailor Thibault Reinhart and professional rigger Julien Barnet - burst onto the sailing scene. Posted on 3 Aug
New Electric Bowsprit Furler from Bamar
An option for 40-60 footers Whilst performance enhancing marine electronics - such as nke - continue to thrive in popularity, more and more people are also choosing to turn their heads towards the automatism of various sailing systems. Posted on 29 Jul
Do I need the nke Man Overboard Module?
A small, portable transmitter that automatically detects M.O.B. As the trend for performance enhancing marine electronics continues to grow, here at upffront.com we have decided to make things simple for our customers: we've crafted six, turn-key, nke autopilot and navigation packages. Posted on 27 Jul
nke Marine Electronics packages
Introducing the 'Cruise' package from upffront.com Due to nke's impressive product range, we also introduced a number of marine electronics packages crafted by Upffront.com. We created these packages to simplify the tricky world of marine electronics, and the result was six turn-key packages. Posted on 19 Jul
LOOP® Products - An Introduction
A whole array of rope-related products: blocks, soft shackles and more LOOP® Products are a German firm who pride themselves on hard work and innovation. Formed in 2005, LOOP® Products is the brainchild of Kohlhoff GmbH - a deck hardware specialist and wholesaler of top brands since 1991. Posted on 12 Jul
MBW newsletters (top)