Adding a slip on a dock

[allanbranch]

My family owns a dock on our property and we're going to add a slip for my 30' morgan.

What things should I consider when designing the slip?

I've never owned a boat of this size and I'd hate to think "gosh I wish I thought to add _____ when I added the slip. I've attached a picture of the dock and a crudely photoshopped idea of what we're thinking. I'm missing steps coming from the corner point down to the new addition, but hopefully this makes sense.