Answer:
-29.7
Step-by-step explanation:
Assuming sea level is at 0, you would first subtract 25.65 from 0 to indicate diving 25.65 feet BELOW 0. Then, you subtract 16.5 from that. Then, add 12.45 to that number to get the answer after the diver rose 12.45 feet.
0-25.65= -25.65
-25.65-16.5= -42.15
-42.15+ 12.45= -29.7
OR 29.7 feet below sea level.