"Phillip" wrote in message
...
I have a question regarding a bass boat and a larger motor.

when I get my boat on plane I know is a small portion of the boat actually
on the water. What effect does trimming the motor up have on the boat, is
there more or less boat actually in the water?

Thanks

Finding the proper trim angle is going to be different for each boat, as
well as load, speed and water conditions.

Trimming the motor all the way down will lift on the transom, force down the
bow and cause the boat to get up on plane. However, once on plane with the
motor in this position will have the largest wetted surface, the most amount
of hull drag and the least speed.

As you trim the motor out, the thrust angle of the prop relative to the hull
is going to change, causing the bow to lift. As you do this, you reduce the
amount of wetted surface and hull drag is reduced, causing increased speed.
When a bass boat is up and running good, there is a small surface called
"The Pad" and a large portion of the boat's hull is out of the water. The
boat is actually balancing on the pad and is running at it's peak. Some
boats, particularly high performance boats have a small pad and the boat
will rock side to side. This is called Chine Walking and depending on the
boat, can be a real handful. A slight down trim or reduction in speed is
the prudent way to handle chine walking, but experienced drivers can
throttle through it and with proper application of some steering manuevers,
eliminate or reduce chine walking to a manageable level.

If the trim angle is proper, you should have a rooster tail behind the boat
approximately the same height as the engine cowl and you'll feel the boat
riding in what I call "The Sweet Spot". If the motor is overtrimmed, the
bow will start to bounce up and down, this is called porpoising. Either an
increase in throttle or a decrease in trim angle will reduce this condition.

Most boats will require a slight down trim in order to turn at speed as
well. Trying to turn at speed, while the boat is on the pad can cause
fishtailing, which unless you're experienced, can create a high pucker
factor.

One thing that you never want to do, unless it's an absolute emergency, is
to chop the throttle completely off while running on the pad. With most of
the hull out of the water, a sudden elimination of throttle can cause the
nose of the boat to drop and dig into the water, causing the boat to do an
abrupt 180! While it might look really cool, I've seen it happen and the
driver was ejected from the boat. Luckily, he wasn't injured, but he could
have quite easily been.

So, in answer to your question, YES!
--
Steve @ OutdoorFrontiers
http://www.outdoorfrontiers.com
G & S Guide Service and Custom Rods
http://www.herefishyfishy.com