Sitka - Submersible Excursion

We'll be in Alaska end of July (can't wait) and my son saw something on the internet about an excursion where you go below in a boat and view underwater life. Has anyone experienced this? Just wondering if it's worthwhile?

Thanks!

I haven't yet seen any comments about this excursion, but from what I've seen on the Web site - [url="http://www.sealifediscoverytours.com/"]http://www.sealifediscoverytours.com/[/url] - it's a fabulous trip, and I'll be on it in June.

Murray