One moment his head was above waterline and the next he was down under again with something wrapped around his leg. Not weed, that much Phobos realised, unless the weed here had somehow mutated and grown muscles or something.
Curling up, the boy felt around in the dark, trying to get a grip on whatever was having a grip on him which was easier said than done. In the end, he opted for kicking the creature clutching at him - hard.