CREATE TABLE table_75735 ("Name" TEXT, "Year" FLOAT, "Landfall" TEXT, "NHC Advisory Number" TEXT, "V ( mph ) " FLOAT, "R ( miles ) " FLOAT, "Saffir-Simpson Category" FLOAT)

What was the highest SaffirSimpson with an NHC advisory of 18?
SELECT MAX("Saffir-Simpson Category") FROM table_75735 WHERE "NHC Advisory Number" = '18'
SELECT MAX("Saffir-Simpson Category") FROM "table_75735" WHERE "NHC Advisory Number" = '18'