Read 'Darker Than Amber' by John D. MacDonald... one of the
Travis McGee series which is well worth while for anybody
who likes boats... very plausible novel about a very
profitable murder scheme, disposing of people by dropping
them off cruise ships.

I believe there are lots of similar schemes/places around. There's an
area in Colorado called the Uncompahgre National Forest where hunters
come from all over the country every year to hunt elk. Locals refer to
it as a place to take someone if you want to kill them and not get
caught. My brother married a women who took him hunting 90 days after
they were married and he wound up being murdered.