Standard Waterat Control Layouts
The standard boom vang arrangement is a cascade system rigged as follows.
A wire block with becket,
either a Schaeffer or Harken (not the wire bullet block size, something stronger). This
is shackled with a strong twist shackle to the reinforced boom vang attachment
on the boom. A wire is attached to the becket, runs down to a similar block
shackled to the base of the mast, back up to the block on the boom (goes
through aft opening to front opening, and then to a Harken triple block. A rope
tail is run between this triple block and a double block hung on the mast, a
short distance above where the second wire block was hung. Two swivel blocks
are hung on either side of the double block to turn each end of the rope
tail down and out to Harken thru-deck blocks that lead the tails through
the diagonal bulkheads and aft along the inside hull/tank join, two a cheek
block on either side that turns the line up to a servo cleat on the seat tank.
The standard cunningham arrangement is a shackle sawn into a hook, hooked
into the cunningham eye in the sail. The hook is swaged to a piece of 3/32""
wire, which runs down to the mast step (continuation of centerboard cap),
thru a Harken single thru-deck fitting on the port side of the step. The
wire turns aft, and at about centerboard pin location ends on a Harken single
bullet with becket. Marlow super pre-strech is lead from the becket to a
cheek block mounted further aft, then back to the single bullet with becket,
and from there through a Harken double thru-deck which brings it through
the centerboard cap, to a Clamcleat, and then to a Harken bullet on an eye strap.
The cleat is on the top of the centerboard cap, port side, aft of where the
centerboard handle when centerboard is down, but in front of the mainsheet
The mast ram (car down) control is key in a 505. Effective control of mast
bend is important in getting the mainsail shape you want. The ram down starts
with a wire shackled (so it can be removed) to the car on the track. A single
wire bullet hangs on the end of this wire. Another wire, deadended to a bolt
through the front of the aluminum mast step fitting, goes through this block,
and down to a Harken double block .....missing...... lead to Harken thru deck blocks
in the diagonal bulkhead, next to the vang thru decks. From there the line
runs aft paralell to the vang line, through Harken cheek blocks which turn it up,
and to servo cleats on the tanks. A simpler variant is to lead the ram
underneath the the centerboard cap, through a Harken double thru deck, to
a Clamcleat on the starboard side of the cap, and then through a bullet block
on a eye strap aft of the cleat.
Mast Pre-bend or Ram Up
In light air, you will probably wish to induce fore and aft bend in the mast
to flatten the mainsail. While spinnaker reaching, the spinnaker pole pushes
the mast back and can invert the mast, unless the mast is constrained. Both
of these are accomplished with the mast pre-bend or ram up control. It can
be as simple as a pin through the ram track (drill a series of holes through
the track), below the car, that prevents
the car sliding any further down on the track, or it could be a mechanical
advantage, so you can adjust pre-bend easily.
There are several variations of the mechanical advantage system. My favorite
is the most recent, which does not require any additional holes to be cut
through the mast wall. A piece of engineering plastic is shaped to the same
size as the ram track. It is mounted above the track on the mast. A Harken
micro cheek block is fastend to it and to the track itself. Thin spectra line
is run from the top of the car, through the micro cheek block, and then down
through the mast gate - along the ram track - two a shackle on a Harken
micro double block. Marlow super-prestrech runs between this double block,
and one mounted on the mast step in front of the mast. The bitter end of
the control line is turned by a thru deck on the top
of the mast step, and is lead aft - underneath the cap - to a cleat mounted
on an aluminum bracket underneath the CB cap. The cleat faces the port
side of the boat. The line then runs through a fairlead, and deadends on an
eye strap to prevent the loose end catching in the 1:4 (bag boat) spinnaker
halyard that also runs down the port side of the centerboard trunk.
Spinnaker Pole Uphaul/Topping Lift
The idea is to have to pole stowed on the boom, or hooked on to the mast, at the
correct height, without having to adjust the topping lift. You need to lead the
topping lift to the correct height on the mast to do this. The topping lift
comes down the mast, and exits on the port side of the mast below deck level. It is
lead through a small block on an eye strap just to port of the mast step, and aft to a cleat
on the centerboard cap. The cleat is normally just a few inches aft of the
mast step. Use thin non stretch line or wire for the toppng lift.
Spinnaker Pole Downhaul/Foreguy
The pole downhaul/foreguy should have a positive stop when the pole is clipped on
the mast so that the pole cannot sky, and has only enough play to allow the crew to get
it on and off the mast. It also needs a shockcord retract so that it retracts as the pole
Waterat accomplishes this by using thin kevlar or spectra. It is led from the pole end,
through a bullet block, down along the mast, through a thru-deck fitting, to a cheek
block bolted underneath the mast step, which turns it so it runs aft through the diagonal bulkhead. It goes
aft to a floating bullet block on the end of a piece of shockcord, and then runs
forward back to the diagonal bulkead. Normally, it is deadended on the forward face
of the bulkhead. When the pole is pushed out, the floating block is pulled
forward until it jams into the bulkhead. This provides the positive stop.
As the pole is brought back, the tension of the shockcord takes up the slack in the
A short piece of shockcord is used to pull the downhaul down next to the pole end,
so that it does not get wrapped around the pole end.
One issue with this system is where to mount the block that takes the downhaul
from the pole end, and turns it so it runs down to the base of the mast. Many
of these are mounted at the top of the ram track on the mast. Lower down would be
better, but the ram tube gets in the way.