Paul, the Houston ship channel originates near the business district at Allen's Landing downtown and runs some 25-30 miles easterly (although looping along it's original waterway called Buffalo Bayou) to Galveston Bay to the east.
The city of Galveston is not nearby, being south southeast of Houston, some 45-50 miles. Actually the port of Galveston is a channel between the main island and the adjacent Pelican Island.
The Texas coast in the Houston area has some natural protection (maybe not much)from the Gulf by the long barrier islands, Galveston Island and Bolivar Peninsula, some 100 miles in extent, almost continous. That said, hurricane Carla in the 60's came ashore and did major.
CNBC is reporting Rita winds at 165.
In edit: BTW I haven't heard anything about NASA Space Center, located just east of I45 about half way from downtown Houston to Galveston. I imagine they are well storm proofed.
CNBC is showing I45 northbound out of Galveston as a very slow moving 3-lane parking lot. They're getting out.
