1981 was the first year for a 22' walk-around,, the 220 Bimini which is a 226 now days. The 222 Bahama is the 228 now days.
1984 they changed the name to Seafarer and used 226 and 228 numbers.
So to answer glacierbaze, if you want to be technical,,1984 is first year of what we know as the...