The renowned happening of Tadeusz Kantor took place on the 23rd of August 1967 on a beach in Łazy, near Koszalin in the north of Poland by the Baltic Sea, as a part of periodic plein-air in the nearby Osieki.
The most famous element of this happening, the Sea Concert, transpired in the following manner:
The audience, composed of beachgoers in their bathing suits were sat on deckchairs arranged in regular rows, so that the first row were partially immersed in the water.
In front of them, several meters into the water, a podium with stairs had been erected. Then came a boat, and a tall man in a black tailcoat alighted and entered the podium. The man, facing the sea, and with his back to the audience commenced conducting the waves.
The man in the tailcoat was a painter and author of the installations, Edward Krasiński.
Tadeusz Kantor directed the entire happening by issuing commands through a speaker.
The famous photography was taken by Eustachy Kossakowski.
It is currently in possesion of the Artists’ Archives of the Museum of Modern Art in Warsaw.
It is probably one of the most often reproduced Polish photographs. Museum of Modern Art reports dozens of requests annually for use for posters, illustrations, book covers, etc..

Source:
Teatr niemożliwy. Performatywność w sztuce Pawła Althamera, Tadeusza Kantora, Katarzyny Kozyry, Roberta Kuśmirowskiego i Artura Żmijewskiego, Zachęta i Kunsthalle Wien, Warszawa 2006.

Czerska Karolina, Tadeusz Kantor, „Panoramiczny happening morski”, Culture.pl 2014, http://culture.pl/pl/dzielo/tadeusz-kantor-panoramiczny-happening-morski