We visited last week and had a great time.
We stayed at Beaches and got a bus from there...I don't think you'd get the same vibe by boat?
We got there at 5ish and watched the sunset, the divers and had a few drinks with a live band playing. It was really niced and relaxed.
There is a small pool you can sit round and the staff will come round with drinks.
We stayed until about 7pm and it was dark by then.
There were loads of buses and taxis coming and going and we felt our 2 hours was just long enough

A party of us ( 8 or 9 ) went last year and had a blast , we hired a mini bus and took in the beaches of Negril before arriving at Ricks about 4 o`clock , 3 of us then had a go at the `cliff jump` and boy it looks a long way down when you stand there waiting to jump off, its all an adrenaline rush ., the cliff divers are awesome , birdman must be fearless , he perches on a small wooden `platform` which looks like a length of 3`` x 2`` nailed to the top of a tree and does somersaults before launching himself out and down , the sunset was slightly obscured by clouds but hey its JAMAICA so its still IRIE MON. Go and enjoy the music and drinks .