Is it possible to shipwreck one's "vessel" of faith, a vessel that's been built up for years of saving faith,per say, and then complete the journey of Life and living Faith by escaping on a raft or swimming the rest of the way? Or relying on God's provision of friendly dolphins?
Yes, If God shows mercy to the shipwrecked person so that they know the truth.
Paul writes about opponents, and a shipwrecked person would be one too.
Notice it says God may grant them repentance.
You can certainly pray for them.
2 Timothy 2:25-26 New King James Version (NKJV)
25 in humility correcting those who are in opposition, if God perhaps will grant them repentance, so that they may know the truth, 26 and that they may come to their senses and escape the snare of the devil, having been taken captive by him to do his will.
People who are shipwrecked get captured by Satan to do his will, so they become God's opponents, and Christians also. Paul says a shipwrecked person has rejected faith.
.
1 Timothy 1:19-20 New King James Version (NKJV)
19 having faith and a good conscience, which some having rejected, concerning the faith have suffered
shipwreck, 20 of whom are Hymenaeus and Alexander, whom I delivered to Satan that they may learn not to blaspheme.