1998 Bayliner Capri floor.

[Scott Danforth]

they are centeredish at best

if no one chimes in, this is what I would do:
at seat base height, go up another 5" and measure width of boat . then measure seats. you want a few inches between the seat and the coaming bolsters. then measure the distance between the seats. this is your walk way. you want that as wide as you can go.

however there are plenty of bayliners out there, so hopefully someone can chime in and measure theirs

 

[JASinIL2006]

I would put them where they seem the most comfortable to you. No rules, here, other than to make the seating work for your needs.