J/70 Owner Guide
Page
© Copyright 2012, J Boats, Inc. All Rights Reserved
10
CAUTION: USE OF A YACHT CLUB SINGLE-‐POINT HOIST OR OTHER NON-‐STANDARD
CRANE TO RAISE THE J/70 KEEL MAY CAUSE DAMAGE TO BOTH THE KEEL AND THE
HULL AT THE KEEL TRUNK.
J/70 keel lifting eye should only be used with the standard aluminum J/70 keel
crane that is designed with a stop to prevent over-‐hoisting the keel bulb and kelp
cutter into the bottom of the hull. Do not attempt to combine the boat lift padeyes
with the keel lifting eye during hoist operations.
Keel Safety Plate
J/70 keel system includes a substantial 316 SS plate that bridges the top of the keel to prevent it from
sliding out of the keel trunk should the boat ever become inverted or beyond a 90 degree horizontal
position. The SS plate is secured to the boat with two bronze nut fasteners on the SS studs mounted on
each side of the keel recess. It is important to install this system properly each time the keel is lowered
into position for sailing and good practice to inspect the system each time the boat is used.
Kelp Cutter
The J/70 keel is equipped with a stainless rod/kelp cutter that travels vertically within a slotted
tube at the leading edge of the keel. Kelp or seaweed is “cut” by pulling up on the kelp cutter
knob (at front end of cockpit) until the cutting blade hits the G-‐10 composite cutting block that’s
molded into the hull. Once the cutter has been used several times, a narrow groove will develop
in the G-‐10 block which will actually improve its cutting action.
While sailing, the knob and blade are stored in the down position which means (on an L-‐shaped
keel) that the profile of the cutting blade projects forward of the leading edge of the keel,
several feet below the waterline. There is a blunt radius on the front of the blade, with only the
top horizontal surface sharp. You’ll find that most weed that catches keels and rudders is
floating, so remains near the top of the foil.
CAUTION – THE KELP CUTTER BLADE IS SHARP AND CAN CAUSE INJURY. WHEN
NOT SAILING, PULL THE KELP CUTTER KNOB UP TO ITS MOST VERTICAL
POSITION (and lash to the boom), SO THAT THE BLADE IS AGAINST THE HULL
AND DOES NOT POSE ANY RISK OF INJURY WHILE WASHING THE KEEL OR
SWIMMING NEAR THE BOAT.
Keel Crane System
J/70 keel crane is a custom fabricated aluminum crane with an integral 30:1 worm gear winch and
Harken 2:1 tackle with floating Harken wire block and twist shackle. The keel crane line is a length of 12
strand 6mm HMPE (Dyneema) with an average breaking load of over 7,600 lbs. (J/70 keel weighs 630
lbs.). The keel crane fits into a socket behind the keel recess under the keel cover hatch. It is a simple
matter to shackle the Harken block to the keel lifting eye to prepare to lift the keel. Keel crane winch is
