There are
1,513 mi
from San Marcos, CA to Seabrook, TX
That's the driving distance. It would take 1 day 1 hour to go from San Marcos, California to Seabrook, Texas.
The flight distance (direct flight from San Marcos, CA to Seabrook, TX) is 1,326.95 mi.
1,513 mi = 1.61 kms