In 1967 he arrived in Singapore and hitch-hiked through Malaysia to Bangkok, (Thailand) and via Kanchanaburi to the Three Pagodas Pass where he spent three months with the pro-U Nu Burmese rebels[1] under the command of General Bo Yan Naing.

From 1970 to 1975, Chas would continue to photograph war, political upheavals, elections, droughts and conflicts in Cambodia, South Vietnam, Chile, Argentina, Colombia, Venezuela, Dominican Republic and Peru.

On 14 February 1968, (during the Tet Offensive) he walked from Cambodia into South Vietnam (via Gò Dầu Ha)[4] and soon thereafter started his career as a freelance photojournalist and cinematographer.

At the end of '68 and beginning 1969, there was a relative quiet in South Vietnam and Chas as well as many of the other "resident" war photographers, left (among others: Sean Flynn and Dana Stone), only to return upon the American invasion of Cambodia.

While in Cambodia, he continued working freelance and in addition started contributing articles (under the pseudonym of Bill Steiner) to the Copley News Service.

[8] In 1982 a couple of art student in Concepción copied Chas' photo of general Pinochet with the premonitory message, "NINGUNA CALLE LLEVARA SU NOMBRE" (No street will bear your name) It was plastered on walls on the evening before the days of national protests.

A couple of days later, after the arrival of Dennis Hopper, Chas was asked by Jerry Ziesmer to report to Francis Ford Coppola: "on how to dress a combat photographer."

From that moment on the role of Dennis Hopper as head honcho (Captain Colby) for Colonel Kurtz (Marlon Brando) was changed into that of a photojournalist.

In 1984 Chas produced and directed a one-hour documentary "The Longest Holiday" a view on the Joys of Aging in Sun City, Arizona which was bought by RAI, ORTF and the BBC.

In June 2019, KINO Rotterdam made a short (32 min) documentary about Chas's life and the images he had taken during the six months he worked as a still photographer on Apocalypse Now.

"The Dutch Angle: Chas Gerretsen & Apocalypse Now" created a lot of interest and was included in the Blu-ray release of 'Apocalypse Now Final Cut'.