First, the good news. It gives some support to the contention that Rassmann was on Kerry's boat rather than PCF 3. It also gives support the contention that Kerry's boat was hit by a mine.
The bad news for Kerry is that it still manages to undercut Rassmann's story. This is from Kerry's own mouth, inserted into the Congressional record:
There was the time we were carrying special forces up a river and a mine exploded under our boat sending it 2 feet into the air. We were receiving incoming rocket and small arms fire and Tommy [Belodeau] was returning fire with his M-60 machine gun when it literally broke apart in his hands. He was left holding the pieces unable to fire back while one of the Green Berets walked along the edge of the boat to get Tommy another M-60. As he was doing so, the boat made a high speed turn to starboard and the Green Beret kept going--straight into the river. The entire time while the boat went back to get the Green Beret, Tommy was without a machine gun or a weapon of any kind, but all the time he was hurling the greatest single string of Lowell-Chelmsford curses ever heard at the Viet Cong. He literally had swear words with tracers on them!
Rassmann, of course, insists that he was knocked off the boat when it hit the mine. This is quite a detailed memory of how Rassmann ended up in the water, so you would think that would give it more credence. But then, we're talking about John Kerry, who somehow claimed to vividly remember being in Cambodia in Christmas, though his proxies now admit that this story is meritless.