Boaters Use a Checklist Before Getting Underway

Boaters Use a Checklist Before Getting Underway

by: U.S. Coast Guard Auxiliary Public Affairs

http://www.uscgnews.com/go/doc/4007/1510923/

How to Trim My Boat - Step 1

Trimming is typically thought of by most boaters as the action that maximizes hole-shot and speed of a boat.  But the scope of this skill goes well beyond momentum... In this multi-part article we will cover the basics of trimming a boat for maximum efficiency and safety.

STEP 1: Available Technology for Improving Boat Attitude

If your boat does not have the hardware covered in this article contact a dealer for propeller or aftermarket options.  Here are some of the typical tools used for trimming a boat  and changing its attitude while under way.

Trim Tabs:  These installed accessories (commonly called “ Bennetts” if hydraulic, also available in electric actuation from various manufacturers) lift the stern while lowering the bow, and are also used for adjusting lateral balance.  Once the tabs are raised above the bottom of the hull they no longer affect the fore-and-aft attitude or heeling to port (left) or starboard (right).

Outdrive Trim (Outboards and Sterndrives I/Os):  Actuating the hydraulic lifts installed on these drive components changes boat attitude similar to trim tabs.  If set in the "down" position, they cause the stern to lift while lowering the bow.  They can also be adjusted “up” which lowers the stern and affects bow rise.   Outdrive trim is primarily used for fore-and-aft attitude adjustment and to increase propeller running angle for improved top end speed.  In multi-engine applications the outdrive trim can adjust lateral balance. This is not the preferred method for side to side adjustments and a loss in efficiency can be expected.

Propellers:  Depending on design, number of blades, and geometry a propeller has the potential to increase both bow and stern lift (fore-and-aft attitude).  The rake angle of a propeller blade plays the biggest role in fore-and-aft attitude over any other prop attribute.  Bow lift can be expected if the blades of a propeller in relation to its barrel slant away from the boat (positive rake angle), while less rake angle increases stern lift.  An increase in blade count, diameter, and surface area also increases stern lift.

Hydrofoil Stabilizers:  Another aftermarket installed accessory item, these change fore-and-aft attitude only.  They are mounted to the out drive's cavitation plate located just above the propeller.  The majority of hydrofoils are designed to increase stern lift to correct for underpowered engines or poor performing propellers.

Balance Tanks / Bladders:  Aftermarket installed accessory items, these are typically used to help balance a boat as fuel is consumed and to increase wake size for water sport enthusiasts.  They are generally placed near the aft (rear) of the boat.  

Passengers and Equipment: Movable ballast can be used to help further balance the boat.  Before adding these additional variables, it is best to master trimming your boat.

With the large variations of possible environmental conditions, boat hull types, and power configurations in the market there is no "one size fits all" guide to achieving ultimate trim.   With some experimentation and the helpful services of a knowledgeable Turning Point dealer, you can achieve a safe, smooth, and fuel efficient ride on just about any boat.   See future articles on “How to Trim My Boat”

Consult your Turning Point Propeller dealer to learn about how our propellers will improve the performance of your boat. Turning Point has been engineering, manufacturing and marketing high-performance, pleasure craft aluminum and stainless steel propellers for over 15 years. Our innovative products are available worldwide through an extensive family of dealers and retail outlets, which can be found on the "Find a Dealer" section of our website .www.turningpointpropellers.  Contact  Turning Point Propellers at  847-437-6800 or at sales@turningpointpropellers.com

How to Trim My Boat - Step 1 - Available Technology for Improving Boat Attitude

By:  TP.  Engineering

Turning Point Propellers, Inc.Published:  2012-08-22