About the author

About the author Henk Aasman: among other marine subjects, I taught celestial navigation to about 250 students during 30 years in the French W.I..

About the author, image Capesterre de Marie-Galante
Capesterre de Marie-Galante, small french island in the West-Indies. Guadeloupe Author picture: No machine-readable author provided, smiley assumed

Nationality: Dutch

Master mariner’s certificat of Competency

Engineer Navigation

Overall, I have been a maritime education teacher for 30 years.

Indeed, the primary objective of this website is to provide guidance and interactivity for the precise calculation of the Line of Position (LOP) using only a sextant and the sun—completely free of charge.

Additionally, identical exercises can be purchased in the store after mastering the basic exercise ‘La Rochelle.

About the author sun dial       concept: The author Henk Aasman
analemmatic sun dial concept: The author mosaic: Mika Rosan Analemma Tracer: Jerôme Savoie

Also, this analemmatic sundial was created by the author using the same formulas as those required in our exercises on this website.

Azimuth and the calculated height.

About the author image lighthous schiermonnikoog image made by my sister
The Dutch lighthouse Schiermonnikoog. Author image: Suzan Aasman (2023) Suzan named this picture “for my mother”.

About the Author: My Professional Marine Experience

About the author, author working as a trainee on M.V. Nedlloyd Rouen  (left on the photo) 1980.
Henk Aasman working as a trainee on M.V. Nedlloyd Rouen (left on the photo) 1980.

I also held the positions of Manager of the GMDSS (Global Maritime Distress and Safety System at Sea) and the Radar Simulator Center.

GMDSS console with Inmarsat C, Navtex, VHF and SSB.
Basse-Terre (Guadeloupe) Radar Simulation Control Panel

Furthermore, the author served as a Marine Officer in the Dutch Merchant Navy for approximately four years.

painter: Jean Verdier

Following that, I embarked on a transatlantic journey aboard a 12-meter ketch, relying solely on traditional navigational tools such as a Plath sextant, a nautical almanac dating back four years, and a small world radio.

During this first voyage from Europe to the West Indies, after spending 24 days at sea, I predicted that we would spot the red light of the south of Martinique in precisely one hour. To everyone’s delight, my prediction came true, leaving an indelible memory for all, including the author himself.

Istanbul (Turkey) image: Amir Pashael