Hey guys, I've been out of school for quite some time but I've run into a situation that involves a bit of calculus and I kinda want to wrap my head around it and figure it out mathematically.. I need some help coming up with an equation for the following scenario.

My boat has a 7' draft, the harbour entrance is 5.5' and the only way to get the boat out of the harbor is to pitch the boat to the right, at a certain degree that will bring the keel from 7' to 5.5' in depth. I need to find out what Degree that is. The keel is 7' deep when the boat is at 90 degrees, so what degree would the keel be at 5.5' deep?

I hope this is the right place to post this and any help would be appreciated. Also if there are any other variables that I need to include but haven't please let me know.

Thanks.