I like my hatches where they'll help me gain easy access to the most volume within my boats. I put my font hatch far enough forward so I can reach most of the usable volume in the bow. The practical limit may be the width of the boat; as it narrows at the bow there may not be enough deck to fit the hatch into. The front of the rear hatch is about a foot behind the rear bulkhead. This lets me put bulky items (tent, sleeping bag) right behind the bulkhead, in the widest part of the boat.