Ok..since only that bath tub is big enough to fit him, I let him play water inside the bath tub and
he enjoyed it alot. He even took some of his toy & put inside the bath tub .
I let him have some fun there before I continue to bath him clean.
Although the bath tub is bit small for him to move around, but seeing his happy face playing with water, I also feel happy.
Maybe I should consider to let Ryan learn swimming in future.