The KSTB call stood for their "Star of the Bay" slogan. Was basically an AC format. Many mentions of local events in the Galveston Bay area. Appeared to be a syndicated format that was surprisingly customizable.
I never got to hear much of KSTB unless I was down in that area...Their signal barely made it to my Cy-Fair location, and has been downgraded since then. It now simulcasts KAYD in B/PA.
Another similar type of operation was (the original) KRTX 104.9 in Galveston. Very few people recall that it was the first station in the Houston-Galveston market to use "The Wave" as a slogan, when it was running a New Age/Contemporary format in the late 80's. I recall they applied for the KGWV calls about that time, but I don't think they were ever actually granted. Signal range was also very limited, blocked in by the (then) KFRD-FM in Rosenberg. KRTX would occasionally make it to NW Harris county after KFRD signed off. The station is now KPTI on 105.3. Any aircheck of the NAC days would be quite a find, on the same rare level as KZRQ.