Window in a seal sanctuary in Hel
Underwater window was replaced due to the damage done during routine hydroinsulation maintenance of the pool. The old one was installed using outdated acrylic-steel tech.
It was required for the previous one to be removed, make a new joint surfaces and install a new window.
The acrylic-to-steel technology comes from the eighties, is labour intensive and does not guarantee such a long service run as acrylic-to-reinforced concrete.