Thanks to everyone who responded to my South American Cruise concerns. We have booked a Panama Canal 14 day cruise in November instead as one of our pals suffers from sea sickness and our new cruise is a calmer journey.
On a totally unrelated subject - Has anyone zip-lined in Costa Rica and if so, how was it? We want to do it but I'm afraid of heights!!!

There was a great post about zipline here by msharmanshaw. I personally would never do it, I'm way too afraid of heights.