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ELDEAN OPERATING MANUAL
NW Explorations
3B5: Trim Tabs
The boat is fitted with a set of Bennett Trim Tabs. These are wide “flaps” attached to the aft
end of the boat, under the swim step at the trailing edge of the hull, operated hydraulically
under the control of the skipper by rocker switches with indicators at each helm station.
At low speeds, up to approximately six knots, the tabs do little, and should be left in the
“Bow Up” position (see below). But at speeds over this range, the tabs begin to take effect
and will help the operator lower the bow for more efficient cruising.
The best way to adjust the tabs is to lower them while watching the “Speed” indicator to
get the highest speed at a given throttle setting by adjusting “Bow Down”. If the tabs are
“Bow Down” too much, the steering will get mushy and speed may drop off a little, and
the tabs should be adjusted “Bow Up” a little. Note that it will take time to make these
adjustments; when the buttons are depressed, they need to be held 2-5 seconds each time
for change to be felt and observed (the best way to see the effect of the tabs is by the knot meter and by observing the
height of the bow relative to the horizon, most easily seen from the lower helm station).
Because the trim tabs are so large,
THEY MUST BE IN THE FULLY- BOW-UP POSITION WHENEVER THE BOAT IS TO BE
OPERATED IN REVERSE
, otherwise the great water forces against the tabs may damage them severely, even tearing them
off the hull!
