Most divers signal to their buddy with a thumb up that they have reached the designated time to ascend to the surface. When the partner comes back with a thumb up then you know it is time to go. Some beginners think that the thumb up means “OK” but after reading this post if you didn’t, now you know it is the signal to ascend. Here are PADI’s 5 point safe scuba diving instructions as taught in there open water coarse remember this acronym “STARS” and never forget it.
S- SIGNAL: Give the clear ready to start ascending signal (thumb up hand signal) and receive a confirmation from all divers that they are aware the dive is ending.
T-TIME: Look at the time indicated on your dive computer to make sure the No-decompression limit wasn’t exceeded. If exceeded prepare to make decompression stops at recommended depths and signal to your buddy diver for a confirmation. Time and fully complete your safety stop.
A-AIRWAY: Look up and make sure there’s a direct path to the surface. Search for obstacles (like boats you won’t want to bang your head on).
R-REACH: Extend your arm above your head signaling the okay signal to the boat or fellow divers at the surface and to protect hitting your head on anything that may be above you. Turn around when ascending to keep track of anything behind you.