Lester Gilbert's Radio Sailing

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Technical & theoretical aspects of RC yacht racing

Updated February 2024

I'm interested in radio-controlled racing yachts, in particular the International One Metre (IOM) class, where I campaign a Pikanto.  When times permit, I'm also sailing in the 6M class with a fine wooden hulled Ravenna.  No longer, but previously I sailed in the Marblehead class with a Quark, and in the 10R class with Graham Bantock's venerable Puzzle.  I took up vane sailing for a while in the A Class and 36R.  For some years I campaigned an Italiko IOM, and before that an Ikon, highlights being various mid-fleet placings at European and World championships.  I also campaigned a Sword A Class, my highlight was 9th place in the World Champs at Gosport in 2005.

My "Bakers Dozen" A Class, built by Graham Bantock in Kevlar to Roger Stollery's design from 1983 and the RA National Champion of that year, has gone to a good home in Norway, courtesy of yvin Halle.

This site is aimed at technical and theoretical aspects of RC yacht racing. In particular, it has a number of spreadsheets to download. Although aimed at the IOM, they should be useful for any non-rotating fractional Bermuda sloop rig.

These pages are intended for educational purposes.
My education particularly (smile), but I hope you find them useful too.
If you'd like to reprint, copy, or link to anything, go ahead,
but do please attribute my words, diagrams, photos,
 spreadsheets, and software to me so others know who to blame.
If you'd like to use anything for gain or commercial purposes, we must talk.
Creative Commons licence at foot of page.


Site news & other interest

February 2024:  I'm assembling a tutorial on the statistical analysis of the kind of data that typically comes from studies of opinion, or the effects of treatments involving human participants.  It is located under "Other Topics" in the section called Psycho Stats & Interaction.  It begins with a Basic orientation covering single sample data and currently extends to Two independent samples, Two dependent samples, One way anova, Two way factorial anova, Two way repeated measures on one factor and Two way repeated measures on both factors data analysis.

November 2023:  A downloadable spreadsheet for calculating the Canvas Wrap of a photo printed to canvas and wrapped to a frame.  Charles Johnson - a scientist and an amateur photographer - has a PDF on colour management, the most straightforward explanation I have read.

October 2023:  Scans of the International Radio Controlled Model Yacht Championship programme and results, August 1975, held at Gosport (UK) -- World RC champs 1975.  How many names do you recognise?  From the programme, an article on Radio sailing history by Norman Hatfield.  Scans of other IMYRU Championships --Durban 1978, Ottawa 1980, Dunkerque 1982, Ullnasjon 1983, Gothenburg 1987, Berlin 1988.

September 2023:  I'm updating the site with some of my articles that were originally published in the American Model Yachting Association's (AMYA) excellent "Model Yachting" magazine, by permission of the Editor.  The first two, on Stiffness (AMYA MY #173) (Fall 2013) and on Trim & Drag (AMYA MY #174) (Winter 2013) *, can be found in the "Design" and "Build" sections.  The rest are listed here:

Bulb cant (AMYA MY #175) (Spring 2014) *
Canoe body yaw (AMYA MY #176) (Summer 2014) *
IOM History (AMYA MY #177) (Fall 2014)
Sheeting (AMYA MY #177) (Fall 2014) *
Lift to drag (AMYA MY #178) (Winter 2014)
Velocity made good (AMYA MY #180) (Summer 2015)
VMG & pointing (AMYA MY #181) (Fall 2015)
Weather helm (AMYA MY #182) (Winter 2015) *
Wetted surface area (AMYA MY #183) (Spring 2016) *
IOM bulb drag (AMYA MY #184) (Summer 2016) *
Boundary layer (AMYA MY #185) (Fall 2016) *
Balance, part I (AMYA MY #187) (Spring 2017)
Balance, part II (AMYA MY #188) (Summer 2017) *
3D printed sail box fittings (AMYA MY #195) (Spring 2019)
3D printed spreader (AMYA MY #199) (Spring 2020)
Kinked kicking strap (AMYA MY #208) (Spring 2022)
Scale models (AMYA MY #208) (Spring 2022)
Adjustable spreaders (AMYA MY #210) (Winter 2022)
2D flow simulation (AMYA MY #212) (Summer 2023)

* Article reports data from wind tunnel, towing tank, or other experimental setting

Site content

The material is classified into the three major headings of Design, Build, and Race.  Anything not fitting that scheme goes into Other Topics (except for Links and Reports which have a place on the main navigation bar).

Under Design are pages on How a yacht works, How aerofoils work, Where lift comes from, How fins and sails work, Appendage design, Hull design, Sails and rigging design, and The boat as a whole.

Under Build are pages on Hull, Fin & rudder, Bulb, Sails, Rigs & fittings, R/C, and Finishing off.

Under Race are pages on Preparation (Boat speed, Avoiding errors, Strategy), During the regatta (including topics on the racing rules), In the race (Boat speed, Avoiding errors, Tactics), and Performance improvement.

Other Topics include pages on International RC racing, Classes, Sailing venues, Event management, Event scoring, Observing, Ancillary equipment, Bulb calculator, Plans, References & book list, Alphard picnic units, Photography, Duplo train track layouts, and Statistical analysis of data using analysis of variance.

Commercial stuff

I previously manufactured an adjustable spreader.


This Web site content is licensed under a
Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License.
This Web site content is to be Attributed to Lester Gilbert.
You are free to Share (to copy, distribute and transmit the Web site content)
and to Remix (to adapt the Web site content)
for non-Commercial use
under the conditions of this licence as long as you Distribute under the same licence.


Some site statistics instead: approx 300 pages, 2400 images, 40 spreadsheets...

...free from those nice folks at NewsNow

2024 Lester Gilbert