Table of Contents


Operation #4: Operate in open water #4.1 The operator is able to:


A: Trim the boat... B: while underway by adjusting the position of persons/gear and engine/drive trim or trim tabs.


Understanding the Element • “Trim” refers to the fore and aft balance of the boat.


• Trim is influenced by the position of people and gear in the boat, position of the drive unit for outboard and stern drive, and position of trim tabs.


• Correct trim increases comfort, boat handing ability, fuel economy, visibility from the helm, and safety, particularly with small boats.


Designing Instruction


• Instruction should include demonstrations of handling under various trim conditions and details of how to recognize and achieve proper trim, including directing passengers/crew to adjust position.


• Include interpretation of trim position indicators if the boat is so equipped.


• Differentiate trim from listing and heeling. Listing refers to static lateral balance while heeling refers to dynamic lateral balance such as caused by the wind.


• Emphasize proper care when moving people/gear while underway to achieve proper trim.


• Make clear connections between maintaining proper trim and safety issues associated with having clear visibility at the helm.


Assessing Performance Level


Successful Performance


Needs Improvement


Unacceptable (Unsuccessful) Performance


3 2 1


The operator:


Positions equipment and passengers/crew to optimize proper trim and list at any speed. Properly uses engine trim and trim tabs to maintain optimum and comfortable pitch and heel. Uses trim to achieve desired cruising speed.


The operator:


Positions equipment and passengers/crew to optimize proper trim and list 80-95% of the time. Spends excessive time in bow high, semi-displacement mode before achieving a plane. While on the plane, allows occasional plowing and porpoising. Obtains desired cruising speed 80-95% of the time.


The operator:


Positions equipment and passengers/crew to maintain optimum trim and list less than 80% of the time. Does not use engine trim and trim tabs to maintain optimum and comfortable pitch and heel (if applicable). Unable to get up on plane because of improper positioning of passengers/crew and equipment, and/or improper use of engine trim and trim tabs (if applicable). Is able to use engine trim to achieve desired cruising speed less than 80% of the time (resulting in boat porpoising or plowing).


Proficiency description


This Technical Support Document was produced in part through USCG grant funds to develop National On-Water Skills Standards. 37 ©2022 United States Sailing Association. Facilitated by Think First Serve.


Element


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80  |  Page 81  |  Page 82  |  Page 83  |  Page 84  |  Page 85  |  Page 86