Date: 201511
Local time of day: 1201-1800
Location: TNCM.Airport, PR
Flight conditions: VMC
Light: Daylight
Aircraft: Small Transport
Operator: Corporate
Operating under: Part 91
Flight plan: VFR
Mission: Passenger
Flight phase: Descent
Airspace: Special Use OCEANIC
ATC / advisory: TRACON ZSU
Reporter organization: Corporate
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Multiengine; Flight Crew Instrument
Human factors: Communication Breakdown; Situational Awareness
Anomaly: ATC Issue All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Requested ATC Assistance / Clarification
Contributing factors: Airspace Structure; Human Factors; Procedure
Primary problem: Procedure

Narrative: When descending into any of the Juliana controlled airports; TQPF; TNCM; TFFJ etc. there is a lack of good procedure between Juliana and San Juan Center. In some cases San Juan Center will drop you early enough out; and in other cases Juliana will understand that we are still talking to center and have us call back. However; often times San Juan Center will want you to remain on their code until the airspace border but Juliana will want to assign you a code 60 miles out. If you do not give a courtesy call 60 miles out Juliana yells at you. However when you do; they want to assign you a code and get upset if you don't switch to their code immediately or if you don't answer them right away because you are still talking to San Juan Center.In this particular case there was no immediate danger; but it is impossible for us as pilots to squawk two different codes (even with dual transponders that probably is not a good idea even if they could work independently). It is also very difficult to be talking to both Juliana and San Juan Center; especially when we should be using the other radio for things like; monitoring company; listening to ATIS; and talking to FSS. It seems to me that there is a bit of a pissing contest between the two agencies and a lack of a standard procedure that allows an easy transition from one airspace to the other. I can see this being a dangerous situation given the right circumstances. There should be some kind of coordination between the two so that pilots can switch from one to the other as they would anywhere else in the world. When you are leaving Juliana they are happy to send you over to Center at 10;500 feet when you haven't even left there airspace yet and Center can't even probably hear you but yet on the way in they want 60 mile away transition. Center however; is not always ready to let you switch yet until right at the boundary. Not always; sometimes they will drop you as soon as you report a descent; but it's not always the case. It seems to be that there is not an established procedure; or if there is; one or both parties are not using a standard transition point. I understand that it is international waters and maybe not clearly defined who controls what; but a simple procedure should be agreed upon for everyone's safety. Mostly us pilots who are stuck as being the mediators between the two facilities.




Synopsis: The reporter perceived a lack of procedures between San Juan CERAP and Juliana Control in the Caribbean Ocean. The pilot called the Juliana controllers ahead of time on his own to get a transponder code that Juliana will want them on.