It's not a kids thing, it was for older teens/adults I believe. It was about a teenage boy who lived on a small island in America, his dad disappeared and was presumed dead. Something to do with lost gold? The boy figures out where the gold is and it's in a tunnel down a well. His girlfriends dad is also after the treasure and he frames the boy for some crime (possibly a murder?) and he takes the gold and flies it away on his private plane. The boy takes his girlfriend and they run away on a boat, in a storm and get wrecked and a I think a fishing boat picks them up?
DH and I watched it ages ago and I can't, for the life of me, figure out what it was called!