Does saving a woman from drowning make the rescuer a Mahram?
Saving a woman from drowning, fire or the like does not make the man who rescues her a Mahram (spouse or permanently unmarriageable relative). This is proved by Ijma` (the consensus of scholars). At the same time, this is not a reason that prevents him from marrying her. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.