Ok...here is what I know about getting to Blue Lagoon on your own.
(First of all, my cruise was not on
DCL ,

and I have actually never been to Blue Lagoon, but this is what I know.)
The ship sponsored excursion (not DCL) to Paradise Island was $27/person. If you wanted to snorkel and didn't have your own equipment, it was $40/person. As a poster already mentioned, you MUST have a life jacket to snorkel on Paradise Island, if you don't have one, you MUST rent one, whether you are with the cruise sponsored excursion or not.
(I've heard that there wasn't a lot to see snorkeling at Blue Lagoon, but I've never been there, so I don't know.)
You can get to Blue Lagoon on your own. But it might end up being close to the same price as doing with with DCL, depending on how much they charge.
1) Get on a taxi going to Paradise Island, it is a large van and they charge somewhere between 4 & 5 dollars per person, which usually includes the bridge toll. Make sure you tell the driver before you get in the van that you want to go to the "Water Taxi's that go to Blue Lagoon." Most everybody else in the van will probably be going to the Casino, but they will stop at the Water Taxi stop on their way to the Casino. (BTW, this Water Taxi stop is NOT the same as the water taxis that are right off the ship that take you to Paradise Island. I guess you could take these water taxis instead of the vans to paradise island, but I BELIEVE these water taxis do not go directly to Blue Lagoon, instead, you would need to get of on Paradise Island, and find your way to the Water Taxis that go from Paradise Island to Blue Lagoon, but don't quote me on that.)
2) Take the water taxis from Paradise Island to Blue Lagoon, I'm not sure how much they charge, maybe somebody else knows, or maybe they know of a better way to geth there....but this is one way. I would guess they charge somewhere between $5 and $10 for the Water Taxi, so you are probably looking at $25 per person anyway. It might be best to just take the shore excursion.
Any thoughts????????
There are also beaches on Paradise Island that you can go to (which is what we did), without having to go to Blue Lagoon. However, I didn't see any place to get a drink on these beaches. So you may not want to do that.
However, LESLIEH, if you are interested in going to a beach to snorkel, but don't care about the drinks, e-mail me know and I'll tell you how to get to a pretty good spot, and it only costs the price of the taxi, about $4 or $5 dollars one way.
blarsenmba@yahoo.com