Adiver is swimming 45 meters below sea level his friend is on the boat at sea level how far apart are they

They are 45 meters apart. 
If the diver is 45 meters below sea level, (-45) and his friend is on the boat at sea level,(0) it would just be 45 meters apart. Just think how far away is -45 from 0? It is 45 away from 0.
Hope this helps! :D

It seems like a trick question but I think 45 metres.