Advice...?
Just the usual as far as hazards. Don't penetrate if you aren't equipt and trained to. The Yukon is covered in large Metridiums. Look close and you will see nudibranches of many varieties. Mostly she is just a big friggin boat. She will be spectacular in another 10 years. I can't wait.
The Ruby has been down much longer and is covered in strawberry anenomes ala rose bowl float. Again, tons of macro here as well as schooling fish. Look for torpedo rays in the sand.
The kelp is the kelp. If you dive the NCI often, you know what it's about.
Have a great dive. If I wasn't working, I would join you.
Terry