Diving text reveal transition on After Effect

Hello,

I need help with an assignment on After Effect, I would like to make text appear on a video where a woman is diving. A wave serves as a transition and can be found underwater while we follow the woman diving.  I would like the text to be revealed while we follow her underwater. I tried to do a tracking but it shows me "analysis failed" because not enough target points I suppose. 

Could someone please help me? I can't attach the video in question, but I hope it will be enough... Thank you for your answers