The hatch window developed from the requests of many who wanted a window, built like a hatch, that would be suitable 'laying back' and facing fored or wherever, and remain waterproof but functional.
The hatch window is commonly used in the centre-front location of hardtops and saloons on Launches, and dodgers on Yachts. It has also been used in tugs and ships wanting the weather proofness of a hatch, but the functioning ability of a window.
These are custom made and can have mitred or radiused corners. Radius option 76mm cut out in the vessel.