Surface means buy truck or boat.
Domestic means an actual state of the United States of America or a possession. To include but not limited to Alaska and Hawaii, or Puerto Rico and Guam. Canada is domesticated, but not domestic in this case. In Canada, for example, I can send one or two books there cheaper than I can send it to another customer here locally. I have to use parcel post which obviously isn't a hardship on me, the customer pays for shipping, unless it deters my customer from buying.