Sea Trials

Surveying Fiberglass Power Boats (2E)

Surveying Fiberglass Power Boats 

2nd Edition

Chapter 17


Possibly the most difficult part of the sea trial is paying attention to the work at hand rather than watching the beautiful scenery go by.

The objective of the sea trial is to prove the operation and performance of the vessel, its machinery, controls and equipment.

This is the point where the sum of the separate parts of the survey come together and the assessment of the performance of the vessel and its overall operation is made.

It was pointed out in the Hull Survey chapter that it is not enough to merely examine a boat in a static condition, but that a most thorough survey involves making examinations while the vessel is underway.

The significance of this is that faulty conditions may show up while the vessel and its systems are under stress, that do not show up while just sitting tied to the dock.

For this reason, the more strenuous the test to which it is subjected, the more likely it is to reveal otherwise hidden faults.

Unfortunately, we don't get to pick the weather conditions for our sea trials, so the client should be made aware of this.

Nearly half the year in my home region, the seas are dead calm or nearly so. This doesn't result in very good sea trials, but there is nothing I can do about except to make sure that the client understands that problems may come to light when the boat is bashing into three foot head seas that did not come to light during the sea trial.

The nature of the sea trial is determined by the nature of the vessel and whatever navigation it was intended to perform. How it is to be performed should always be conducted on that basis.

A houseboat intended for cruising on inland rivers and lakes is viewed in a different light than an oceangoing yacht. The sea trial of a mega yacht is a vastly different event than for most smaller boats.

The objective is always to determine if the vessel is seaworthy for the environment in which it will most likely be used.

This is not to say that a client won't purchase a houseboat on the Lake of the Ozarks and transport it to Miami and attempt to operate it there.

That's why it was earlier recommended that the surveyor should always "qualify the client" and find out his plans for the vessel. If he plans to use a vessel that is clearly unseaworthy for a particular navigation area, it is only prudent that the surveyor advise him accordingly.

Copyright© 2004 David H. Pascoe
(Additional spaces are added for easy screen reading.)


Table of Contents: Chapter 17

17. Sea Trials 387

Special Considerations 388
Doing it Right 389
Taking Control 390
Vessel Speed 391
Handling Characteristics 392
Main Engines 394
Engine Performance 395
Engine Instruments 396
Back Down Test 396
Shaft Runout 397
System Vibration 398
Helm Response 398
Autopilots 399


Copyright© 2001 - 2005 David H. Pascoe

Surveying Fiberglass Power Boats
- 2nd Edition

Soft Cover
480 pages
Publisher: D. H. Pascoe & Co., Inc.
Published: 2005
Language: English
ISBN-10: 0965649601
ISBN-13: 9780965649605

Price: $69.50
In Stock



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:

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.

Biography - Long version

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