Cockpits, Motors and Trim
Surveying Fiberglass Power Boats
by David Pascoe
The subject of Cockpits, Motors and Trim has been included here as a separate chapter because it is so important that the uninitiated understand that the design of a boat, and how it is trimmed, has a tremendous affect on its performance and seaworthiness.
It is a three part subject because all three are inter-related. This chapter is not about engines per se, but how outboard engines affect the performance and sea worthiness of a boat beyond just propelling it.
There is a very prevalent misconception amongst novices that, because the builder built it that way, it must be okay.
I've already gone to great lengths to explain why this isn't true, so please don't automatically assume that all boats are seaworthy. Some aren't, and some may have serious deficiencies.
Many readers aren't old enough to remember the Chevrolet Corvair. A lovely little rear engine car that was the technology leader of its day. It only had one small problem: at high speed, or when roads were wet, it wouldn't steer. Why not? Well, there quite simply wasn't enough weight in the front end to keep the wheels on the ground. At certain speeds and conditions, the car wouldn't steer. I owned one, and I loved it, but that car almost did me in one day. A silly design mistake, although a very deadly one.
The Definition of Seaworthiness
While I'm at it, let me give you the true definition of seaworthy, which is actually a legal term, one that has its root in maritime law.
A vessel is seaworthy only for a particular voyage (in your case a day of boating), meaning a particular body of water, at a certain time of the year, under the normally expected conditions, with a competent operator, crew and all necessary supplies and equipment.
In other words, the seaworthiness of a boat is dependent on who, what, where, when and under what conditions. There is no definition of seaworthiness for the vessel alone, divorced from the circumstances in which it is operated.
So what the devil does this have to do with cockpits, motors and trim? By itself, a boat cannot be seaworthy; conversely, by itself it can be unseaworthy. Sound crazy? Then consider the following.
(Additional spaces are added for easy screen reading.)
Table of Contents: Chapter 6
Definition of Seaworthiness
A Bit of Design History
Basic Design Types
Standard Motor Well
The No Motor Well Design
Hull Integral Platforms
Cockpit Decks, the Weak Link
Deck Height Above Water Line
Single or Twin Engines
Trim Tabs Versus Power Trim
- 2nd Edition
by David H. Pascoe
Publisher: D. H. Pascoe & Co., Inc.
David Pascoe - Biography
David Pascoe is a second generation marine surveyor in his family who began his surveying career at age 16 as an apprentice in 1965 as the era of wooden boats was drawing to a close.
Certified by the National Association of Marine Surveyors in 1972, he has conducted over 5,000 pre purchase surveys in addition to having conducted hundreds of boating accident investigations, including fires, sinkings, hull failures and machinery failure analysis.
Over forty years of knowledge and experience are brought to bear in following books. David Pascoe is the author of:
- "Mid Size Power Boats" (2003)
- "Buyers’ Guide to Outboard Boats" (2002)
- "Surveying Fiberglass Power Boats" (2001, 2nd Edition - 2005)
- "Marine Investigations" (2004).
In addition to readers in the United States, boaters and boat industry professionals worldwide from over 70 countries have purchased David Pascoe's books, since introduction of his first book in 2001.
In 2012, David Pascoe has retired from marine surveying business at age 65.
On November 23rd, 2018, David Pascoe has passed away at age 71.