S.C. Code § 39-17-310
All watermelons shipped in carload lots from any point within this State as "Graded Melons" shall be graded according to the following standard, that is to say:
Grade 1 shall weigh not less than 44 pounds with car average of not less than 46 pounds;
Grade 2 shall weigh not less than 40 pounds with car average of not less than 42 pounds;
Grade 3 shall weigh not less than 36 pounds with car average of not less than 38 pounds;
Grade 4 shall weigh not less than 32 pounds with car average of not less than 34 pounds;
Grade 5 shall weigh not less than 28 pounds with car average of not less than 30 pounds;
Grade 6 shall weigh not less than 24 pounds with car average of not less than 26 pounds; and
Grade 7 shall weigh not less than 20 pounds with car average of not less than 22 pounds.
Such melons of whatever grade shall have been picked from live vines of a merchantable quality and shall be ripe, free from rotten ends, and from necks and blisters.
The grading of watermelons, as aforesaid, shall be optional with the shippers.
S.C. Code § 39-17-310