I was an aerodrome/approach procedural controller at Sangster International (MKJS) for over 5 years and I now working radar approach. Let me throw something in the mix. Separation is something that for the most part tends to be at the discretion of the Authority. In other words FAA sets its rules and JCAA (Jamaica Civil Aviation Authority) sets its own. On final approach and within 10 miles of the aerodrome, aircraft must be no closer than 3 miles. Beyond that, they must be no closer than 5 miles within 60 miles of the radar head, and beyond 60 miles the separation is 10. Now if an aircraft is on a visual approach the separation is at the discretion of the following pilot. With regards to arrivals and departures, there is nothing written (such as 6,000 ft and airborne, or "2 increasing to 3") that speaks to it, except that the wheels of both aircraft should never be on the runway at the same time. Seeing that our runways in Jamaica are all under 10,000 ft, pretty much everybody is going to be airborne within 6,000 ft so that rule couldn't possibly apply apply here. Since 2003 when I first got my approach control licence, I have only ever issued a go-around instruction once. I try my best to not let it happen, with late landing clearances, S-turns, 360 turns, slow-and-dirty, you name it. For the most part, the pilots appreciate it because a missed approach procedure is the last thing anybody wants.