Answer:
46 feet below sea level
Step-by-step explanation:
First, we start at -50 feet, which is 50 feet below sea level. If he swims 8 feet up, we should add the 8 feet. -50 + 8 feet which would give us -42. If he descends another 4 feet from the point where he is at right now (-42 feet), it would leave us with the point where he would be which is -46 feet. This is because we are adding the -4 feet, he descends to the -46 feet which he is already at.
