I'm guessing that the "ocean-weary raft" is a metaphor for someone who has a disability or is challenged by life in some way, and has learned to overcome it.

As you know, I prefer Japanese forms to be free of poetic devices, or at least they are to be used very sparingly. We need to know who this person is, and why this person has changed so dramatically.

Most importantly, the last line of a senryu should make the reader go "Ah hah!" not "Huh?"

It is near impossible to discover hidden abilities when all you are able to do is survive.

The ocean is a daunting place to stay afloat. In terms of the symbolism, the raft, whether large or small, does not allow you to escape the clutches of Maya - the grand illusion. Upon recognizing that you have some control over the madness (i.e. coming into calmer seas), you are capable of discerning the true source of the turmoil. Only then do you realize that the "raft" - your self - is unbound by strictures of material entanglement.

If you see the Buddha swimming in your path, fly over him.

I love the metaphor here, Michael - a well thought out piece with a lovely end full of hope