Most of the pictures are shot by ourselves. Should we have used a stock photo, you can find the source and license here:
- https://www.maxpixel.net/Water-Pressure-Gauge-Pressure-Gauge-2292979 - license: CC0
- https://pixabay.com/de/freediving-tief-unterwasser-wasser-1383103 - license CC0
- https://www.flickr.com/photos/criminalintent/86428258/sizes/o/ - license CC BY-SA 2.0. The image has been cropped and further adjusted.
- https://www.pexels.com/photo/animals-aquatic-blue-character-511017/ license: https://www.pexels.com/photo-license/