An American man took his partner to Tanzania and proposed to her by swimming to an underwater window she was stood next to and holding up a sign that said 'I can't hold my breath long enough to tell you everything I love about you', before turning it over to reveal a marriage proposal on the other side. Telling his partner all the things he loved about her turned out to not be the only thing he couldn't hold his breath long enough to do underwater, however, as shortly after getting out the piece of paper he drowned:
https://www.bbc.co.uk/news/world-africa-49783851
What wacky and also potentially lethal way would you like to propose to your partner?