Figure: CAR Region, from Eddie's notes.
Regional differences from the ICAO standard can be found in ICAO Document 7030 and your Jeppesen Airway Manual. Both of the sources, however, can be out of date. See International Operations Manual / Regional Introduction for ideas about getting up-to-date information.
As countries around the world update navigation systems and procedures, it becomes increasingly important to speak with somebody who has been to the airport recently or have a contact in country with local knowledge. As we say in the military, there is no substitute for boots on the ground.
What follows comes from the references shown below. Where I think it helpful, I've added my own comments in blue.
This region is moving from a mix of navigation requirements to the system of Performance Based Navigation outlined in ICAO Document 9613. Current navigation requirements are available on Jeppesen Airway Manual Air Traffic Control pages and Chapter 4 of each region covered by ICAO Document 7030.
[ICAO Doc 7030 Amendment 1, §CAR, ¶18.104.22.168.] RNAV 10 (RNP 10) A lateral separation minimum of 93 km (50 NM) may be applied between flights operating on oceanic routes or areas:
Keep in mind RNP 10 is an exception to the rule of Required Navigation Performance standards, "RNAV 10" retains the "RNP 10" designation for matters of convenience.
As of 3 Jan 2014 every country in the Jeppesen Airway Manual, Air Traffic Control, State Rules and Procedures, Caribbean is listed as WGS-84 compliant except the Netherland Antilles, The Jeppesen WGS-84 website, http://www.jeppesen.com/company/publications/wgs-84.jsp, lists their status as unknown.
More about this: International Operations / World Geodetic System 84 (WGS-84).
[ICAO Document 7030, Section CAR, Paragraph 4.2.1] A minimum vertical separation of 300 m (1,000 ft) shall be applied between FL 290 and FL 410 inclusive in the following FIRs: Barranquilla, Central America, Curacao, Georgetown, Havana, Houston Oceanic, Kingston, Maiquetia, Mazatlan Oceanic, Mexico, Miami Oceanic, Panama, Paramaribo, Piarco, Port-au-Prince, Rochambeau, Santo Domingo and San Juan.
More about this: Procedures & Techniques / Reduced Vertical Separation Minimum (RVSM).
Each country departs in some ways with the ICAO standard and common US practices. Pilots should always refer to the Jeppesen Airway Manual, Air Traffic Control, State Rules and Procedures pages for each country on their itineraries for differences with ICAO Standards, Recommended Practices and Procedures. More about this: International Operations / US versus ICAO.
The following are a sampling of some of the differences, there are many more. You should check the Jeppesen Airway Manual State pages for every country you takeoff, overfly, or land.
It is easy to be complacent in the Caribbean but every country's Airway Manual pages deserve a look. For example, you cannot always used 123.45 for communications (Turks and Caicos), a "contact approach" sometimes means a "visual approach" (Bahamas), and you might have to request engine start at some locations (Netherland Antilles).
[ICAO Document 7030, Section CAR, Paragraph 22.214.171.124] WATRS in flight contingency procedures for loss of navigation capability, strategic lateral offset, and weather deviation are ICAO Doc 4444 compliant and are also covered by the WATRS Plus web page: www.faa.gov/about/office_org/headquarters_offices/ato/service_units/enroute/oceanic/ [FAA Notice WATRS Plus Ops Policy/Procedure Update]
Saying their lost communications standards are ICAO Doc 4444 compliant should alert all U.S. pilots that they are different than what is used in the United States.
More about this: Abnormal Procedures / Lost Communications.
[ICAO Doc 7030, §CAR, ¶126.96.36.199] For flights in oceanic areas outside the ATS routes network, the position shall be expressed in terms of latitude and longitude as follows:
ICAO Doc 7030 - Regional Supplementary Procedures, International Civil Aviation Organization, 2 2008
ICAO Doc 7030, Amendment 1, International Civil Aviation Organization, 8 January 2009
ICAO Doc 9613 - Performance Based Navigation (PBN) Manual, International Civil Aviation Organization, 2008
Jeppesen Airway Manual