The dive site is about forty five minutes East/North-East from Reykjavik which is on the east coast of Iceland. If you have rented your own car, it is relatively easy to drive there, but easier to use a scuba diving organization if you want to dive or snorkel. Using one of these services keeps you from having to bring your own scuba equipment. Remember, the water is about 2-3 degrees Celsius (35 - 37 degrees Fahrenheit) so you'll need cold water gear to make the dive or snorkel for that matter.
Remember, this is as cold of a scuba dive or snorkeling trip you will probably ever make. You'll want to be sure to have the right equipment to avoid hypothermia in a BIG way. At this water's temperature, you could pretty much be dead within 5 minutes of entering the water. One positive thing about dry diving suits is if you need to loose a few pounds, they won't show while wearing the gear.
Sue (the one on the left) became so cold at the end of the first dive, on the surface, that we had to place her into one of the vans that took us to the dive site to warm up. Another diver, because there was a leak in his dry suit and a lot of water got in, was forced to cancel his second dive and stay in the van with the engine running and heat on. We were afraid that he may have needed medical attention, but thankfully not.
The crevice where we were diving is filled with spring water which comes from melting glaciers (and rain) from around fifty miles away. This water is super clear, but also super cold! You can drink directly from this water with no ill effects. This is necessary during scuba diving since the air in your tank is so dry. I had to do this twice myself during the dive(s) to stay hydrated. The water had zero taste. The foreground water in the photo below is where the water comes out of the ground, then under the small land bridge forward, then into the main crevice which is a separation between the North American tectonic plate and the Eurasian tectonic plate.
After getting all of the equipment on, you will be lead down a set of stairs with the diving guide waiting below. Luckily, we were the first divers in the water the day we went, so everything was beautiful and un-touched. It's a lot of work just getting into the water and a lot of care must be taken to not fall in, especially if you have a dive mask which happen to have bi-focal lenses (Ahhhhh, age is wonderful!).
Once you get into the water, it is only 33-35 degrees Fahrenheit! This is the reason for the dry suits. The suites place a layer of air between you and the water, and since air is much easier to heat up than water, your body quickly warms it up and you become quite insulated. The feet and hands can get a bit cold, but that is minimal. Your face/head gets extremely cold as soon as you put them into the water, but your body adjusts to warm them up quite quickly.
One of the diver's who accompanied us on the dive, borrowed Sue and my camera and took this fabulous picture. I'm in the foreground/Center (tall bubbles), Sue is ahead of me and to the right and the dive master is in front of us to the left (you can only see his bubbles and one of his fins. Even though Sue and I are PADI diving instructors, we were smart to get a dive master to show us the area as people have died in this crevice, not a good way to end a vacation.
To the west, the North American Tectonic plate is moving west, and the Eurasian Tectonic plate is moving east. There is an area along the fisher we were diving which is narrow enough to touch both plates as they are moving apart from each other. In these pictures, our left hands are touching the Eurasian plate, and our right the North American plate.
Even though Sue was very cold (she has a comfort range of about 2 degrees (78 to 80 Fahrenheit), she still loved the dive and could even smile a bit.
During the progress of the dive, there were two or three areas where the water became very shallow. There was also a lot of fine silt on the bottom that, if stirred up, would cloud up the water for possibly quite a long time. So, as a diver, you need to be very careful to not stir up too much or the people behind you, or even yourself, won't be able to see where they are going. The picture below shows Sue skillfully using her cavern diving skills to navigate the water without stirring up any silt at all.
I purposefully (yea, right) kicked up some silt just to show you how a tiny bit can begin clouding up the water pretty badly.
Sue used, what they call a 'Frog Kick' to avoid hitting her fin's onto the ground causing the silt to kick up. It could take hours for this material to settle down, especially if there isn't much of a current moving the water.
The dive is about 30 minutes long, and since the water is so cold, you use up quite a bit of air in your tank. So, you're pretty happy to see the exit point. A bit of a hike and about 15 minutes later, you're drinking hot chocolate and getting ready for the next dive!