FYI Kingy.
Rear inspection ports on 1827 are offset (to the outer gunwale) with a single central stringer (12mm x 10mm), in the vertical orientation. I inserted 5" ports compared to 4" on 1765. I ensured there was sufficient space between the gunwale and the stringer as the latter was fitted. With the larger holes and their offset the ease of access is incredible. I have no issue with trapping on the transom, even with the inspection ports' location. Trust Photos tell the story.
![[Linked Image]](http://i840.photobucket.com/albums/zz329/FibreW/Inspectionportflange_zpsed6a28c8.jpg)
![[Linked Image]](http://i840.photobucket.com/albums/zz329/FibreW/Inspectionportflange2_zps8ea88d51.jpg)
The extra ply ring is planed flattish, thinned to zero in the middle, to reduce the curvature impacted on the plastic ring and improves tightening,sealing and removal.
![[Linked Image]](http://i840.photobucket.com/albums/zz329/FibreW/P1030329_zpsfd4f8715.jpg)
Main beam inspection port, offset also.