Is the bottom of a 1989 CAROLINA SKIFF 1450 supposed to be flexible on the bottom underneath not on the front?

Not really sure where you are talking about on the boat - but Carolina Skiffs are fiberglass - which is a little "flexible" but still should be strong enough to where you can't bend anything by hand, if you are talking about the floor - there is most likely wood on the bottom between 2 sides of fiberglass - if the wood starts to rot - the fiberglass will become weaker