Regal 3300 Owner's Manual page 177

When running in heavy seas press the "bow down" position which will
assist the vessel to cut through the waves. This will produce a drier
and more comfortable ride. In a following sea run the tabs in a fully
retracted angle for maximum outboard drive response.
Sometimes you can watch the bow spray or stern wake and the rooster
tail (mound of water produced by propulsion units). In a bow up
position the spray is far aft to the hull, the wake is high and the rooster
tail is high.
When trimmed or in the bow down position, the bow spray is farther
forward, the wake and rooster tail are smaller, and positioned further
behind the vessel. Also, when trimmed you will notice that tachometers
show an increase in rpm's.
Rectifying A List
https://www.boat-manuals.com/
Your vessel can use the trim tabs to rectify a list.
The trim tabs adjust the boat's attitude in the
direction the helm rocker switch is pushed.
If the port bow is high, push the left-hand "bow
down" direction on the dash rocker and the port
bow will lower. If the starboard bow is high, push
the right-hand "bow down" direction and the
starboard bow is lowered.
Features
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