Andy replies:

Thanks to all who answered. It is as I hoped, that is, that any
SJxx would satisfy the code.

By way of explanation to those who wonder why I asked :

This is a local code required by the Tarrant County Water
District, which governs all construction on the local area lakes.
The code is very restrictive, and often very arbitrary on some of
the regulations. The inspectors are not PEs, and just go by
the letter of the code...As far as the electrical, the local guy
has no idea of what SJ means, but will enforce it exactly without
accepting any " but this other cord is much better" explanations.

He is a nice enough guy, but very by-the-book, especially on those
subjects he is not well versed in...... but that's OK....

So, in order to remain friendly with him/them (very important
around
here in small town Texas ), I don't try to deviate but rather
follow the code to the letter, as they do in their interpretation.

The county allows me to do all wiring myself (as owner) down to
the
320 ASL (above sea level) markers, but below 320 it must be done by
a licensed master electrician --- (very expensive for 50 feet of buried
ROMEX
and sub panel --- about $1000 ). The lake is at 315 ASL.
So, I did the job myself to the 320, and will just run an extension
cord
the rest of the way to the dock ---- not a big problem at all.....I
only want
a light and a radio...... I am allowed to do it if the cord is
"SJ"....

Thanks again guys for the input.

Andy in Eureka, Texas