Or is it the number of passengers that triggers a COI requirement and then the tonnage license.
That matches my understanding as well. If the vessel is
not inspected, and is less than 100 tons, it can be operated with up to six passengers by an Operator (OUPV). If the vessel
IS inspected or carries more than six passengers, then a Master's license is required.
Here's some of the OH SO FUN legal text from the Code of Federal Regulations:
TITLE 46--SHIPPING
CHAPTER I--COAST GUARD, DEPARTMENT OF HOMELAND SECURITY
PART 15_MANNING REQUIREMENTS--Table of Contents
Subpart E_Manning Requirements; Uninspected Vessels
Sec. 15.605 Licensed operators for uninspected passenger vessels.
Each uninspected passenger vessel must be under the direction and
control of an individual licensed by the Coast Guard as follows:
(a) Every self-propelled, uninspected vessel as defined by 46 U.S.C.
2101(42)(B), carrying not more than six passengers, must be under the
direction and control of an individual holding a license as operator.
(b) Every uninspected passenger vessel of 100 gross tons or more, as
defined by 46 U.S.C. 2101(42)(A), must be under the direction and
control of a licensed master, pilot, or mate as appropriate.
US Code:
(42)
Uninspected passenger vessel means an uninspected vessel
(A) of at least 100 gross tons as measured under section 14502 of this title, or an alternate tonnage measured under section 14302 of this title as prescribed by the Secretary under section 14104 of this title
(i) carrying not more than 12 passengers, including at least one passenger for hire; or
(ii) that is chartered with the crew provided or specified by the owner or the owner representative and carrying not more than 12 passengers; and
(B)
of less than 100 gross tons as measured under section 14502 of this title, or an alternate tonnage measured under section 14302 of this title as prescribed by the Secretary under section 14104 of this title
(i) carrying not more than 6 passengers, including at least one passenger for hire; or
(ii) that is chartered with the crew provided or specified by the owner or the owner representative and carrying not more than 6 passengers.