It seems my hatches are leaking. Where do I even start and can I replace thes hatch covers?
Try looking here for hatch covers.
http://topkayaker.com/index.php?main_page=index&cPath=18&zenid=a3i5p2mgs79qmhov67lavp3o43
Did you see my recent thread on leak testing?
https://forums.paddling.com/discussion/2936003/leak-testing-tweaked#latest
The most common places for leaks are:
Skeg box, fittings
Bulkheads
Deck fittings (screws, bolts, rivets, etc)
Hatch covers
Hull abrasion/punctures
Harmony carries Perception parts.