Uncle Leo --
As a DM who works out of LA and has been on the Sand Dollar and to the channel islands many times, I can assure you that you will be fine on this boat. My shop takes student divers on this boat to the Channel Islands all the time.
[Ed - I was not able to read the initial email when I wrote this reponse, so I made some assumptions from what I remembered reading but was unable to confirm them in real time ]
Most likely you will do Santa Barbara -- which holds a sea lion rookery with thousands of sea lions. This is an easy dive -- 25 foot sandy bottom and one of the most amazing experiences you'll get. There's also a reef on the south end that has a massive, beautiful kelp forest -- depth ranges from 20 feet on top of the reef to a 60 foot sandy bottom off it. It truly is a treasure and one of my favorite dive spots in the Channel Islands.
The other stop is most likely Catalina. Again, we take student divers for their open water certifications to this island almost every week (I'm doing it in two days).
I have never been to San Clemente -- but then I've never been on the three-day liveaboard on the Sand Dollar (my trips are Friday through Sunday).
In regards to what you should bring, beyond the basics, I would recommend a dive knife, a light, and, of course, a dive computer. I personally have a titanium knife (lighter and less maintenance). If it's a calf-mount knife, strap it to the inside of your thigh, to reduce the chance of kelp entanglement.
In regards to dive computers -- buy'em or rent'em. One for every diver in your group. Whether you buy or rent, it's money well spent. If you're renting, just make sure it's fresh -- you don't want to rent a "dico" that went into "deco".
Bring a light because there's a lot of critters in the crevices. There's lobsters, eels, octopuses, urchins, starfish, sea hares, the bright orange Garibaldi's with attitude, sea bass, sea fans, kelpfish (they look like kelp, imagine that!) and the amazing nudibranchs (spanish shawls). If you want to find these guys, you have to move very slowly along the reef, checking into all the holes and doing your best "Where's Waldo". A lot of newbies think they need to cover ground to see interesting things, but that's not true.
I also recommend traversing the kelp line at the base of the reef. The kelp anchor themselves to the rock so there is a distinct interface at the point where the sandy bottom meets the reef. You might see massive schooling fish moving along the island just off the kelp line, with barracuda and the larger sea bass hiding just inside the kelp line, waiting for a meal.
If you peer out towards the sand, you might catch a glimpse of a stingray or bat ray. To find them, look for an inexplicable trail of low-viz, sandy water originating from a single spot on the sandy bottom. Most likely it's a ray, feeding. They sit on the bottom and flap their wings, which generates a current of bottom detrious that flows into their mouths. The current stirs up the sand and leaves that low-viz trail behind them. I flushed six in one dive not too long ago! I also once tailed a Pacific Electric Ray -- all 200 volts worth! (That was on Anacapa).
In regards to the Sand Dollar, there are two bunk areas, one in the bow (through the galley), and one astern. My recommendation is get there early and grab a bunk in the stern area. They sell out fast because people who know -- know. It's in the back, behind the engines, so there's less bouncing. You should also consdier buying some earplugs. I use Hearos.
If anybody in your crew has *any* issues with sea-sickness, then you need to plan well in advance for this. I've made trips to the outer Channel Islands over a dozen times. Most people get through it fine. Some people are prone to seasickness. (My mother, for example, with over 150 dives). That said, there are prescription anti-emetic meds you can get that are stronger than Bonine, that work. The specific one I'm thinking of is delivered in a patch behind the ear -- it's a time-release anti-emetic -- I've seen it countless times and every diver I've met who has this patch swears by it. But it requires a prescription. Plan ahead. The boat will not turn back from a three day cruise to take care of one seasick puppy. Even if you're not susceptible, get your own prescription, just in case.
One other note [as I'm reviewing some of the comments] -- California diving is unlike most other [warm water] diving, in that the divers are assumed to be competent individuals who can make dive plans and dive w/o a supervisor. If you go to Bonaire, for example, all divers will be expected to trail behind a divemaster who will take you on a "tour." In California, you set out in groups, on your own, with your own dive plans, based on the site briefing that the DM or the Captain provides you.
That said, if you don't feel confident about setting out on your own, you should approach the DM with your concerns, and he or she will "appropriate" an experienced, qualified, guide for you. [And for the record, this guide should be tipped].
In regards to the Sand Dollar -- it's a great boat. The departure time will most likely be 2:00AM (it's a six-hour motor to the outer islands), but there will be a required briefing at 10:00pm or so. I'm not sure what your particular schedule will be, but show up early, grab your bunk, set up your gear, wait for the briefing (where you will be told when to be back), and then go have dinner.
All in all, you have no reason to fear this trip. Don't get scared about the scubaboard talk of depths and currents and all that crap. I always check the current before dropping divers in, and if there's a ripping current, we move the boat. Your DM is your best friend.
Taking the Sand Dollar to the Channel Islands is well within your capabilities, and it's great diving.
I'm looking forward to a trip report.
Wilton
[Edit: I have gone back and reviewed the posts leading up to this one and I have a few comments: -- 1) A shore dive is not doing to prepare you in any way for this. Forget that advice. 2) If one of your crew is already a cold-water DM, and he's going to accompany you, then you're better than fine.]