When Harry dived under the waves, Severus wondered if he had done the right thing. But since Harry had not been ready to talk about his family, he had decided that a little recreational therapy was in order. Help could not be given to those who were not prepared to receive it. So, all he could do was make it easier for his master to cope. He settled in for the wait. Who knew if the boy remembered to come up in time for the Gillyweed to expire?