Was Philip Vian the officer who boarded Altmark?

Was this the same Philip Vian who boarded Altmark?

Yes, Vian commanded HMS Cossack during the Altmark incident, although the official account says he remained on the bridge until the ship had been secured.

Philip Vian commanded HMS Cossack during the Altmark incident. The official account keeps him on the bridge until the ship had been secured. Command responsibility therefore does not mean that Vian personally led the boarding party. The distinction separates his role from later retellings of the most dramatic action.