Being the sea God's friend has its pros and cons, pros outweighing the cons. He had your back around the sea, whether he was or wasn't present. You didn have to worry about getting hurt while at the sea.
Getting back to the reality, you and your friends decided the relax in the sea. Take a swim, joke around, just enjoy yourselves. One point went to another, and the two of you started to push each other into the water. One of your friends however got reckless, and didn't wait for you to get your bearings before pushing your head back into your sea.
Out of the shock you took a breath and inhaled water, so you tried to swim back up but a wave pushed you down, blocking your air. You started seeing spots when you felt strong, and big arms wrap around your waist and pull you out of the water. You coughed and coughed, trying to get the water out of your lungs. All whilst your friends swam just a bit away in fear from you and the... Diety holding you. The diety? Poseidon. And to make it even worse? He was pissed.