Lester Gilbert's Radio Sailing

Home Design Build Race Links Reports Other Topics


Technical & theoretical aspects of RC yacht racing

Updated July 2022

The site is now HTTPS compliant, courtesy of those fine folks at IONOS who provided the necessary SSL certificate and installed the required .htaccess file in the root directory.

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, in the Marblehead class with a previously well-maintained 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.  Until recently I also campaigned a Sword A Class.

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

July 2022: 

I have constructed a worked example of the engineering formula for lift to go with some earlier comments on how aerodynamicists are still are not 100% agreed on why a surface produces this force called lift.

Some racing in the Marblehead 2022 Nationals at Datchet Water was in choppy water and high wind.  I had some trouble tacking, and revisited some comments on tacking I'd published earlier about rudder throw and feeding the rudder into the tack..  I also found the boat would sometimes "hobby horse" itself to a stop, and so revisited some earlier comments on inertia.

June 2022:  The pandemic has returned me to playing with Duplo trains.  One page has comments on the different generations of Duplo track and their dimensional changes, and another page has comments on the construction of a reliable linked switcher system module for "computational" track layouts.

April 2022:  Kim Klaka has written a paper on surface finish, predicting the performance gained by smoothing the hull of a DF95 with different grades of sandpaper.

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 Terminology.

Commercial stuff

I've developed sticky-backed gauges that can be purchased from SAILSetc.
I previously published Larry Robinson's booklet on making model yacht sails using blocks, low stock running out at SAILSetc.
I've manufactured a Limited Edition adjustable spreader that, until stock runs out, can be purchased from SAILSetc.


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

2022 Lester Gilbert