Morena, a scuba diver, used the expression below to describe her position in relation to sea level. 0 + (negative 15) + 6

Which statement could describe the diver’s movements?
Morena started at 15 feet below sea level, then dove down 6 more feet.
Morena started at 15 feet above sea level, then dove down 6 more feet.
Morena started at sea level, dove down 15 feet, then dove down 6 more feet.
Morena started at sea level, dove down 15 feet, then rose up 6 feet.