MDMD: catching up

[Don Corathers]

I'm running some distance behind the MDMD, having arrived just last night
(with great pleasure) at the Vroom household, and working my way through the
several hundred accumulated posts in my inbox.

I hope the list will forgive this retrograde post, but I wanted to see if
anyone could shed any light on a language note that as far as I can tell
wasn't discussed the first time through:

"Some would call her a Frigate, though officially she is a couple of guns
shy, causing others to add the prefix 'Jackass,'--a nautical term." (36:1-2)

Is it? I'd appreciate hearing from anybody who has encountered this usage
before.

Slang dictionaries I've consulted have not been informative on the matter,
but I can think of a lot of instances in which "jack" as a prefix is used to
indicate inferiority, or a counterfeit or ersatz quality. There's jack shit,
meaning not even quite as good as shit. Jackleg, which has the sense of
"makeshift." Jack off. Jack knife, not quite a real knife. In certain
working class restaurants in the midwestern U.S., the only fish on the menu
is called jack salmon, which is actually cod, breaded and deepfried. (It is
my astonishment at this phenomenon that first caused me to reflect on the
meaning of "jack," some years ago.)

This all seems consistent with the Seahorse being labeled a Jackass Frigate
because it doesn't qualify as a real one with the requisite number of guns.
After the first reference, Pynchon (or Capt. Smith) takes the trope in
another direction, adapting the combat tactics of the jackass to a ship
called horse.

Any of you jack tars have any insight into "Jackass" as a nautical term?

Don