canning is the tendency for the mid-section of the hull
to deform when subjected to stress. For example, if you haul and block some boats and don't properly support the keel
in the right spot, the hull
will "oil can" spreading out and deforming.
Older, more lightly built boats will oil can progressively as they age as the fiberglass
weakens under repeated stress cycles. It's why buying
a boat that has been proudly advertised as having completed a circumnavigation
is not a good idea. It will have hundreds of thousands more stress cycles on the hull than a lightly used example.
Oil canning in a chop means that the hull flexes...either visibly or audibly...as in all the cabinetry down below creaking and complaining.
If you're looking for a comparable, better built boat, see if you can find a Nordic
34. They are speedy, well built, and really fun to sail.