I mean "pump it up". Pump until your calves are aching, so that the tubes have as much pressure as you can get in them from the footpump. Then pump some more.

The boat will handle much more than the factory spec of 3 PSI. We inflate to about 6 PSI for testing in the shop.

Then, spray with a soapy water solution (boat soap, whatever - we use diluted liquid ivory or inflatable boat cleaner). You will see foaming where ever there are small leaks (pinholes or seam leaks) or big bubbles where there are bigger holes. See attached image as a sample of what you are looking for.

If you see that foaming around the seams (sometimes you have to wait a few minutes if they are really faint leaks [we call those "foamers"], but they will appear. If they do, the boat has likely lived it's useful life. Hard to say, for sure, without looking at it. So, if you want to fly me and my wife to Italy, I will gladly perform the inspection and the service on the Caribe ;-)

Good luck and happy cruising.

Don't forget to hyper-inflat the chamber(s). This is key in finding the leaking points in the tube.

Stephan