USCGC Bristol Bay

USCGC Bristol Bay was built in 1979, making it 47 years old. It is one of 1,718 hulls in this registry delivered that year, a cohort whose median tonnage is 2,382 GT. Across the whole of the 1970s the registry holds 17,331 vessels, median 2,774 GT. The median build year across the entire registry is 1995.

IMO numbers are issued in broadly chronological blocks. Within 500 either side of 8635150 this registry holds 28 other vessels, whose median build year is 1962 and which range from 1907 to 1993. That places this hull’s registration in the same part of the series, consistent with its recorded build year of 1979.

Its IMO number, 8635150, carries its own check digit. The first six digits are weighted seven down to two and summed — 8×7 + 6×6 + 3×5 + 5×4 + 1×3 + 5×2 = 140 — and the last digit of that total, 0, must equal the seventh digit, 0. It does, so this number is well formed.