Short Percy moment. Excuse the spelling and grammer mistakes i made this in five minutes.

A Clump of Seaweed

Percy's gaze shifted from the clouds to the sea below his boat. Hazel and Frank had passed out at the other side of the boat snd for some reason he knew it wasn't a bad unconciousness, Hazel was somewhere with Frank and they were both safe. He didn't worry, he knew they would keep each other safe.
Staring into the murky depths of the Pacific Ocean he thought of the one thought that was always nagging at the back of his mind. A beautiful blonde girl with cloudy gray eyes. Annabeth, his girlfriend. The only thing certain in the life he couldn't remember. He was so sure of her. Percy suspected this was why he still remembered her.
He sighed. Missing someone you dont even remember doesnt sound all that bad, but the fact he cant remember her too well WAS the troubling thing. It made him think even more about her.
Staring at the water, he saw a dark shape emerging from 50 or so meters down. Of course, being a Son of Poseidon -Neptune, he kept reminding himself- gave him the ability to 'see' much more than a mortal would underwater. If see was the word, it was more like feel. The clump of whateveritwas was about the size of his fist and for some reason, the tide has no effect on it. Waves were thrashing about yet it didnt waver its straight path up to right beside Percy.
He leaned over the side fo the boat more. The clump bobbed up to the surface.
Seaweed. A ball of seaweed.
For a moment percy stared at it.
Then there was a flash in his brain and he could almost feel a wire in there connect. With a yelp he fell backwards to the bottom of the boat holding his head.
A voice played the words over and over in his head. A voice he hadn't heard in eight months. The seaweed (maybe a gift from Dad?) had triggered a bit of memory. It was barely anything to remember, but it was enough to hold on. Enough to keep him sane. Enough memory to keep him holding on to Annabeth like a drowning man to a life preserver.
Seaweed Brain
The nickname she had for him. He remembered now. It played over and over in his head as he lay on the bottom of the boat.
Seaweed Brain Annabeth's voice said as it kept in time with the sea.