Trim and Balance
Trim is the attitude of the boat fore-andaft
and side-to-side. Your boat should
travel through the water with the bow a
few degrees higher (Figure 3-19). Under
most circumstances, that is the best trim.
You have several ways to adjust the trim.
1. Load passengers and equipment alternately
positioned to achieve proper trim.
2. Use your outboard or I/O motor trim
adjustment. This causes the engine
to rotate so the lower unit is closer to
(adjusted in) or farther away (adjusted
out) from the transom. This will affect
fore-and-aft trim.
3. Use trim tabs. These are hydraulically
adjusted metal plates on each side of
the transom. Normally, the plates are
even with the bottom of the boat. The
boat can be trimmed by adjusting one
or both plates downward so they intercept
the flow of water and raise that
corner of the transom. By using trim
tabs you can adjust both fore-and-aft
trim and side-to-side trim.
What are the effects of fore-and-aft
trim? If you trim the bow up, the boat may
accelerate because you are reducing the
amount of hull in the water and the resultant
friction. You may experience a greater
pounding from the waves. However, you
may find that the boat fishtails from side
to side. Also, if raised too far, the boat may
begin to porpoise (alternately rising and
falling bow), which you should prevent.
If you trim the bow lower, you may
experience better steering and the sharp
bow may soften the ride as it cuts through
the waves. With the bow down too much,
you may take water over the bow.
BOATING COURTESY
AND ETHICS
1. Respect the Rights of Shoreline Property
Owners
2. Low Speed Boating in Restricted or Congested
Areas—usually 6mph or less.
3. Render Assistance to Others in Distress
4. Give Consideration to Sailing Vessels
5. Show Courtesy to Fishing Boats
6. Control your boat speed
7. Obey no wake/ limited wake restrictions
8. Refraining from careless, reckless, or
negligent operations on the water, control
boat noise
9. Observe and operate in accordance with
the homeland security measures in Section
7.
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Figure 3-19. Examples of trim and balance