That's still not a universal mandatory sticker. In fact, it is not required except as proof of pre
payment of the Customs' fee, or as proof of payment on first arrival of the year,
and it appears to be not required at all for private vessels in many circumstances, per the exemption cited.
19 CFR 24.22. ...
(e) Fee for arrival of a private vessel or private aircraft—
(1) Fee. Except as provided in paragraph (e)(3) of this section, the master or other person in charge of a private vessel or private aircraft must, upon first arrival
in any calendar year, proceed to CBP and tender
the sum of $27.50 to cover services provided in connection with all arrivals of that vessel or aircraft during that calendar year
....Alternatively, prepayment may be sent by ...
(3) Exceptions. The following are exempt from payment of the fee specified in paragraph (e)(1) of this section:
(i) Private pleasure vessels of less than 30 feet in length, so long as they are not carrying any goods required to be declared to CBP;
(ii) Any private pleasure vessel granted a cruising license under § 4.94 of this chapter, during the term of the license; and ....
§ 4.94 Yacht privileges and obligations.
(a) Any documented vessel with a pleasure license endorsement, as well as any undocumented American pleasure vessel
, shall be used exclusively for pleasure and shall not transport merchandise nor carry passengers for pay. Such a vessel which is not engaged in any trade
nor in any way violating the Customs
laws of the U.S. may proceed from port to port in the U.S. or to foreign ports without clearing and is not subject to entry upon its arrival in a port of the U.S.,
provided it has not visited a hovering vessel, received merchandise while in the customs
waters beyond the territorial sea, or received merchandise while on the high seas. Such a vessel shall immediately report arrival to Customs when arriving in any port or place within the U.S., including the U.S. Virgin Islands
, from a foreign port or place.