Hi,
Not sure if this is old news but saw this 1944 spearfishing and freediving documentary presented by the Sea-Net Company of Los Angeles on youtube.
Sea-Net
https://www.youtube.com/watch?v=-tjwkYjoyoQ
Few others worth seeing:
Plongée dans la Baie - 50's
https/www.youtube.com/watch?v=WVoYcwuTDA0
Par 18 Mètres de Fond (18 Meters Deep) - 1942; - Jacques Yves Cousteau
https://www.youtube.com/watch?v=OlTyUagouCM
EPAVE (1943) - Jacques Yves Cousteau
https://www.youtube.com/watch?v=shv9f3rJ9cU