Ok, if we are talking about padangbai area (blue lagoon), I have a few dives there and I can tell you a little bit about the area.
If we are talking about Tepekong, then I have no experience and you can ignore the rest of this message.
First off, I have to say that being a beginning diver there myself I was able to handle whatever the blue lagoon area gave me, however I already had about 12 dives under my belt at that time and got the tips of my fins wet so to speak. I was comfortable enough to carry a camera and take decent pictures, swim in any angle, swim in cross surge, and manage my buoyancy with relative ease.
If you are going in cold, I would suggest going to Menjangan first and doing a mild drift dive or maybe go to calm Secret Bay (Gilimanuk). Yes, it's clear across the island, but the experience in finning, buoyancy management, and general equipment familiarity will be worth it - not to mention the time spent calming your nerves a little.
Alright, so Blue Lagoon for me (May 07) was very surgy... did I spell that right? That is to say that the water rushes in one direction then pulls you back the opposite way the next. This is very tiring if you are trying to fight it... don't. You will burn up your air very fast and you will give yourself a deceiving level of exhaustion. (I learned this the hard way.) Oh yes, I felt a little spent underwater, but once I surfaced I was a lot tired.
So once you get used to the surge, it isn't so bad, but there was not a place in that area that didn't have least a little surge. Correction... we did do a wall that didn't have detectable surge, but once we got back to the sand shelf there it was again.
Just be careful while under surge... things tend to move faster than you expect while the surge is pushing and you could injure yourself, your gear, or someone else... or someone could accidentally run into you...
All that sounds ominous, sure, but it is all just words of caution in our sport. We relegate ourselves to the waters of natures womb where we are the aliens and things are never familiar. However, once you spend a few minutes or a few dives under surge, it will become second nature to you and you will be swimming with the best of them.
If you are thinking about diving those islands nearby (biaha, Mimpang, [FONT=Verdana,Helvetica,Arial][SIZE=-1]Tepekong?[/SIZE][/FONT]) I would suggest against it at first. There is Heavy current there at times and for a newbie diver, it can be a LOT to deal with. Current is not something that is constant... (especially that time of year when the seasons are in transition) and when an area is calm one minute, the current can whip up the next. That's not to say you shouldn't go... just go with experience under your belt and with a very experienced guide. But , like I said... I have no experience there, so take my advice for what it's worth.
If you are looking for a good guide I can tell you about my experience with Aquamarine... just send me a pm and I'll be happy to answer any questions you have.
Chris