There is a saying in diving – plan your dive and dive your plan. What does this mean? It is simple. Before you even get to the site, you should have a briefing at the dive club or school for all members of the party.
You will discuss where you are going to dive and you will plan it out. This includes the route to be taken, the bottom time as well as the decisions revolving around how much air is left in the tank of the person that has consumed the most air while on the dive.
The party will also discuss what will happen in the event of separation. The standard plan for that is to circle for two minutes and then surface – no exceptions. More info at Padi.
Once on site, you will team up with your dive buddy. You are both to stay within arms’ reach of each other during your dive and you are not to separate. You will then proceed to survey the site and the dive leader will confer with other experienced divers to ensure that entry point is accessible and not too rough, that there are no heavy currents or swells and that everyone is in a fit state to dive. The team will then proceed to kit up and once you have done so, you will do a buddy check with your diving partner. This involves making sure that everything is secure and safe, air is turned on and BCD is inflated to ensure that you float when you enter the water. The team should stay together and not deviate from the diving plan agreed on during the earlier briefing. Another thing to look out for is nitrogen narcosis, which can lead to feelings of being drunk under water. Rising a few meters in depth will usually make the sensation dissipate. Always look out for each other, it is the most important thing in diving.