All the boats pictured on this site were designed by Westlawn alumni. Click here to see a gallery of alumni designs.

Westlawn alumni are prominent in
the marine industry. Click
here to see more.

Click here for information on Westlawn's short continuing education courses.

Click here to sign up for Westlawn’s free email journal, The Masthead, with: technical information, what’s happening at Westlawn, and boating industry updates.

Click here to order
books, apparel and accessories.

Course # Module 1
Principles of Small Craft Naval Architecture

Course # Module 1 Objectives

Describe the design spiral

Comprehend and discuss the basic laws of flotation and describe the basic physical laws which state how various propulsion systems work.

Solve basic algebraic, geometric, and trigonometric problems after completing this math review.

Discuss the meaning of a set of hull lines, calculate displacement using Simpsons Rule or the Trapezoidal Rule, locate the center of buoyancy of a hull, and compute wetted surface, and perform a weight study and locate a hull’s center of gravity.

Discuss and apply the concepts involved regarding the nature of frictional, residual and wind resistance and be able to make recommendations to reduce resistance. Calculate righting arms and righting moments at any angle of heel, analyze stability curves, and comprehend the principles of trim and flotation.

Create and prepare presentation drawings and proposals for new yachts.

Use the required drafting instruments to properly draw lines, curves fair sweeps and other figures needed to draw working plans and apply what you have learned to draw an outboard-profile elevation and general-arrangement plan.

Create and draw and fair a complete set of hull lines, prepare a table of offsets, and a set of hydrostatic calculations for a hull lines drawing.

Obtain a passing grade on a series of written examinations demonstrating that the student attained the required knowledge in the subjects presented in this course and can apply the knowledge to correctly answer the questions and problems presented in the examinations. .

Course # Module 1 Goals
The overarching goals of this course are to enable students to:

Analyze the meaning of a set of hull lines and to calculate the various physical characteristics that describe a boat.

Discuss and break down the nature of frictional and residual resistance and be able to make recommendations to reduce resistance.

Describe the mechanisms involved in transverse metacentric stability and dynamic stability and acquire a comprehension of the principles trim and flotation.

Develop the skills required for manual marine drafting.

Draw and fair a complete set of hull lines

Obtain a passing grade on a series of written examinations demonstrating that the student attained the required knowledge in the subjects presented in this course and can apply it to correctly answering exam questions and problems

This course prepares the student to work as an apprentice to yacht and boat designers with production boat building companies or at firms engaged in private practice while continuing his/her studies. It is the prerequisite to course # Module 2.

Employ a segment of the design spiral to solve a typical design office problem.

Explore several alternatives in order to arrive at the best solution.

Present best solution graphically in the form of a preliminary sketch.

LESSON 8: Stability 2 - Longitudinal Stability

Trim and Flotation
a. Change in level flotation
b. Immersion Calculations

Longitudinal Stability
a. Longitudinal GM
b. Longitudinal Moment of Inertia of Waterplane

Calculations for Change of Trim
a. Moment to trim 1 inch (or 1 centimeter)
b. Correcting out of trim conditions

Design Considerations
a. Variable Loads
b. Comfort Zones
c. Roll Period

Dynamics
a. Pitching
b. Heel and Trim in Sailboats
c. Pitchpoling, Chine Walking, Porpoising
d. Trim Tabs

LESSON 9: Review
Topics lessons 1 thru 8 as needed to clarify concepts or methods

LESSON 10: Introduction To Marine Drafting

Design/Graphics/Communication
a. The design Process Revisited
b. Where do ideas come from?
c. Level 2, 2, 3, and 4 design phases
d. Sketching

Drawing Instruments and Media
a. Equipment and Materials List for Manual Drafting
b. Drafting Tables
c. Pencils and leads
d. Media
e. Scales and Planimeters
f. Ships Curves, splines, and Spline Weights

Layout of Sheets and Scales

Lettering

Practical Exercises

Computer Aided Drafting

LESSON 11: Drawing Of Hull Lines

The meaning of a Set of Lines

Relative Importance of Various Lines

V-Bottom hulls

Round Bottom Hulls

Layout

Drawing the Designed Waterline

Sketching in the Section Lines

Purpose of Diagonals

Buttocks

The Fairing Process

The Offset Table

Parallel Buttock Principle

Form and Proportion

A working Procedure for Drawing a Set of Lines

Hull Line Examples
a. Contemporary High Speed Deep-V planing hull
b. 42’ Medium Displacement Sailing Yacht
c. 43’ Sportfisherman
d. 22’ Contemporary V-Bottom Runabout
e. 13.7m IMS Cruiser/Racer