slight bulge in side of boat
My guess is you have developed a supercritical eye. I had an occasion a number of years ago to investigate some tabbing on a bulkhead on my Ranger 26. Although there was no damage, I learned to "see" bulkheads on everyone else''s boat!!!
What you have is a hull laminate that is laid up and cured. Typically, laminates will creep or shrink about 2% while curing. A few weeks later, the bulkeads are tabbed into place. They adhere to the cured hull laminate and undergo there own creep (or try). The resulting "pull" induces some stress in the hull laminate. Over time the stress elastically relieves itself, not before a minute deflection is created, just enough to bend the light while sighting down the hull. Cored laminates, Tritons hull laminates pre-date these, make this less visible from the exterior. (Read about Larry Ellison''s sled in the Syd-Hobart race pulling the tabs right off of the inner laminate!!!)
Things to watch in the hull at bulkheads are punching shear action created by slamming in to a wharf finger or glancing collisions. These will show up as star fractures in the gelcoat.
Of more concern on a boat of that vintage is the integrity of the bulkhead materal.
Now go see if you find the other bulkheads on the Triton or you neighbor''s boat. Bet you can.