Here is a "recollection" for you.

There were five taipan 4.9s(dpn 65.3) at the 2002 Spring Fever regatta.
There were two Isotopes(dpn 74.2), J.P. Ayers and John Riley, starting with them.
There were seven Tigers and six F18HTs.

There was one f16/taipan at the 2003 Spring Fever, racing in the Open-A Spin Class.
There were no Isotopes.
There were nine Tigers.

There were six Isotopes at the 2004 Spring Fever, racing as Isotopes.
There were no f16/taipans.
There were 19 F18s.

There were four Isotopes at the 2005 Spring Fever Regatta.
There were no f16/taipans.
There were 16 F18s.

Do you recollect who won the 2004 f16 North American Championships.

Where are the 2005 Championships being held?