Both Mambo Hybrid and Royal Golden are excellent watermelons. Mambo Hybrid started ripening right after Mama's Girl water melon, and we already consumed around five fruits or so. Royal Golden seems to be a bit later ripening, we cut our first ripe fruit on July 18th.
Mambo Hybrid fruits are medium in size and green striped. The flesh is very sweet, the seeds are black, and the rind is thick. Excellent melon.