what does the plot diagram for the life of pi look like?

The link below will show you what the diagram should look like;

The following are key facts you can use when making your diagram. You are correct that there are two climaxes. Be sure to show the areas of the plot (main) that come in between.

Your rising action begins with the family setting sail for Canada.

The stories first climax is the sinking of the Tsimtsum. Pi's entire family, the ship's crew, and most of the animals aboard drown. Pi, along with a Royal Bengal tiger, fight for survival aboard a lifeboat in the middle of the Pacific Ocean for months. Your second climax comes with Pi's eventual landing in Mexico.

The falling action takes place when Pi is rescued in Mexico. He is interviewed by two Japanese officials who fail to believe his story.

I think you can figure out the rest; it's pretty simple!