There are two 'variations', both required
for return entry under this Customs & Immigration "Local Boater Option" and DHS "DTOPS" programs.
One is the Local Boater Option
that allows return verification to ports "south of" essentially Vero Beach FL. Each person on board must appear before
leaving the county at a designated custom office and physically present a valid US passport, etc. That person is issued a numbered permanent card.
When returning you phone into the correct customs office, report the card number, answer a few question including your exact Lat/Lon .... Thats it - hassle free no need to 'trapse off' to a far distant international airport or international port of entry to be interrogated and present your US passport. The return entry or 'clearing-in' is entirely accomplished by telephone. MUST be a US citizen with valid passport to qualify and MUST enter 'specified' ports or areas to use.
more info - CBP Announces Local Boater Option for Florida Boaters - CBP.gov
GREAT PROGRAM, especially if you often return to S. Florida, etc.
The second is a REQUIRED special numeric ID
for the vessel or aircraft, obtained (online) from the DHS ... "DTOPS program". You receive an adhesive 'sticker' with serial number which must be placed at the usual 'boarding position' of the vessel. more info - https://dtops.cbp.dhs.gov/
This is required for reentry into the US to ANY port
(or international airport), & not only those ports that accept the Local Boater program. Each vessel or aircraft MUST have
this 'sticker ID' to return & return to the US.