Posted on

Earth’s Tectonic Plates with Prescription ScubaPro Dive Mask

Scuba Diver in dry suitin clear water in Iceland with a scuba pro d mask with lenses installed by See the Sea RX

Diving in Iceland

Iceland, the land of fire and ice, is renowned for its breathtaking landscapes, from towering glaciers to majestic waterfalls. While I spent much of last year in England, I was able to find a deal on last minute flights to Iceland with the idea of exploring Iceland’s hidden gem for adventure seekers: scuba diving between the tectonic plates in water a degree or two away from freezing. While my flights were inexpensive, Iceland as a whole is expensive (something to definitely keep in mind). Packed with my scuba pro d mask and prescription lenses installed in our lab in Houston and a bunch of warm clothes, I was able to get a quick feel for Iceland’s tourism. The trip was a great experience, but I am not in a rush to return (I am, primarily, a spoiled warm water diver). In this blog, I will fill you in on my trip- things to do in Iceland, and some considerations for dive masks in cold water.

Just for context, my trip was in January/February 2024.

Scuba Diver in dry suitin clear water in Iceland with a scuba pro d mask with lenses installed by See the Sea RX
In the cold clear water in Silvia with my custom prescription lens scuba pro mask.

Scuba Diving Between Tectonic Plates

One of the most exhilarating experiences Iceland has to offer is diving at the Silfra Fissure in Thingvellir National Park. There are two main options: Snorkeling in a dry suit (no certification required) or you can dive through the fissure. You are required to have both a dive certification as well as a dry suite certification to participate. The water hovers around 35 degrees year round.

The outing to Silfra cost near $300 including transport from the hotel as well as all equipment. You can bring your own equipment if you wish, but be sure your regulators are serviced and intended for cold water use. I did bring my prescription scuba mask as well as the Sealife phone case which I have been using more than my traditional dive camera set up on these quick trips. All the pics I took were on my Iphone (14 pro max at the time) using the Sealife case.


The dive is short, about 30 minutes and led in small groups with a certified instructor.


Overall it is a unique once in a lifetime experience.

Cold water prescription scuba mask concerns

Some divers contact us wondering if our prescription dive masks will work in near freezing or freezing water temperatures. As you can see with my mask, they hold up well. A few things you can do to prevent damage to the lenses: Try to acclimate the mask to surrounding/water temp before submerging. Going between extreme temperatures can cause the laminate to fracture.

Non diving Iceland Activities

While scuba diving between tectonic plates is a highlight of any trip to Iceland, the country offers an array of other activities in which to indulge:

  1. Golden Circle Tour: Discover Iceland’s iconic sights, including the mighty Gullfoss waterfall, the geothermal wonders of Geysir, and the historic site of Thingvellir National Park. I did not have time to take part in one of the Golden Circle Tours, but they remain one of the more popular options.


  1. Glacier Hiking: Strap on crampons and traverse the otherworldly landscapes of Iceland’s glaciers. Guided tours provide insight into glaciology while offering stunning views of ice formations.


  1. Whale Watching: Set sail from Reykjavik or Husavik for a chance to spot majestic whales, including humpbacks, orcas, and blue whales, in their natural habitat.


  1. Northern Lights Hunting: During the winter months, chase the elusive aurora borealis across Iceland’s dark skies for a mesmerizing display of dancing colors. I missed out on seeing the northern lights the one night I went out. The tour does offer a voucher to try again within a year or two, but it is unlikely I will be back. This was also not a favorite of mine as the first half hour of the tour was picking up other tourists at other hotels (and thirty to forty five minutes of drop offs at the end) and then driving around in a mini bus to locations which may offer the chance to view the lights. The tour staff were friendly, but I would probably find another way of doing this if I was to go again. 


  1. Relax in Hot Springs: Unwind in Iceland’s geothermal pools and hot springs, such as the iconic Blue Lagoon or the secluded Secret Lagoon, surrounded by stunning landscapes. I chose to go to Sky Lagoon which is a bit newer and located a little closer to the center of Reykjavik. My pictures of Sky Lagoon are seen on the right.
A view of outside the sky lagoon center in SIlfra. Water is seen in the horizon. A sign is in front of the building.
Horizon seen over warm water in Sky Lagoon.
Picture of Josh


Josh is an optical technician and owner of See the Sea RX. He is a PADI instructor and rebreather diver- he has been involved in diving for more than 20 years. He has also worked as a sergeant at the Harris County, Texas, Sheriff's Office, which included time as the instructor for the dive team. Josh also holds a masters degree in data analytics from Texas A&M.

Single Lens Dive Mask and Prescription Lenses

Single lens dive masks such as the scuba pro gorilla mask, atomic aquatics venom (& venom frameless) have become increasingly popular with divers due to their increased field of view as well as offering comfort for some divers with more

Read More »

Reading Lens Options for Scuba Masks

Trouble seeing your gauges? As we age, we lose the elasticity of the lens of our eye, which makes focusing on closer objects more difficult. Presbyopia, as this condition is called, can be frustrating on land, but for us scuba

Read More »

How much is a prescription dive mask?

How much does a prescription dive mask cost? One of the most frequent questions we receive is how much does a prescription dive mask cost. Prescription dive masks can run between $100 to slightly over $500. Factors such as lens

Read More »
Posted on

Rebreather Diving (With my Prescription Dive Mask) on the Fu Sheng Wreck in Sint Maarten

Rebreather diving in Sint Maarten

One of the ways we are differentiated is the fact that we are divers, not just opticians and optical techs. While the last two years have been challenging for us and others in the dive industry, I was finally able to start getting back in the water this year. The video above highlights a recent awesome dive we we are able to do on a wreck in Sint Maarten. For those wondering, I dive a prescription scubapro d mask with single vision lenses. 

I like to write about some of my dive travels with my own prescription dive mask and share them with you all.

In this article, I will also cover specific prescription dive mask concerns for rebreather divers.  (Be sure to check out my video above highlight the whole dive).

Dive mask and scuba equipment.
My Scubapro d mask with prescription lenses sitting on my Hollis Prism 2 rebreather.

What is a rebreather?

A diver underwater with a rebreather diving along a wreck
Aiar diving his prism 2 rebreather on the Fu Sheng wreck in Sint Maarten

In Scuba, we have a compressed air tank attached to a diving regulator (a first and second stage). Every time we inhale the regulator provides us (normally) air (or nitrox, or even other gases, depending on the dive) at the surrounding pressure, so our lungs can inflate. Every-time you exhale, all the air in your lungs exits the regulator as bubbles. The human body, however, is not so efficient as to extract all the available oxygen in a single breath of the same gas, so the bubbles contain a significant amount of wasted oxygen. If there was a way to recycle this air, you could extend your time diving.

On a simple level, this is what a rebreather accomplishes. Instead of all your exhaled air exiting as bubbles, you exhale into a counter-lung. The exhaled air then moves across a scrubber removing the carbon dioxide. As the oxygen in the breathing loop decreases, you either manually add, or the rebreather adds pure oxygen to the loop to keep your breathing gas at an ideal mixture. 

Prescription dive mask concerns for rebreather divers

If you are a rebreather diver, and like me need corrective lenses, there are a few unique concerns that open circuit divers don’t face. 

While heads up displays and computers for recreational divers have recently seen a surge in popularity (like the Scubapro Galileo HUD), they are a mainstay in rebreather diving. Rebreathers either utilize a heads up display (HUD) with a series of different color lights to indicate different rebreather conditions or a computer with a full digital display that can provide more information than the more basic HUDs. The most popular HUD computer is the Shearwater NERD, which I personally use on my Prism 2 now. 

The shearwater NERD uses a special lens to focus the display when the diver is looking at a distance, despite the computer sitting inches away from the diver’s face. This allows the diver to be watching his or her surroundings while also having the dive computer screen in focus. If the diver utilizes bifocals or readers in their dive mask, however, the near vision portion of the lens is not suitable for viewing the NERD (While beneficial to a standard light HUD). For rebreather divers who utilize bifocals or reading glass for near vision, we generally suggest using only distance lenses on the side of the mask they view the NERD (normally the right eye).  For more information on our bifocal lens scuba mask options, please read my article here. 

We are also able to produce fully customized lenses that include a reading section at the top of the lens instead of the bottom of the lens, where the NERD is placed, so the diver can use the top of the lens for photography or other macro work. 

Whether you dive a rebreather or open circuit scuba, our diving experience allows us to help you pick the right prescription lens for your needs. Feel free to give us a all or shoot us a message. Our prescription lenses are installed in house in our lab in Houston and are able to provide corrections for astigmatism, double vision, and other unique needs.

The Fu Sheng wreck in 110 feet of water in Sint Maarten- A great dive for a rebreather.

Diving the fu sheng wreck in Sint maarten/st. martin

A dive boat on the surface of the water
Dive Sint Maarten's boat waiting for us at the surface following our hour long dive on the Fu Sheng wreck.

During my time on St. Martin, I dive the Fu Sheng wreck, a dive I have been trying to do since arriving on the island. The wreck, nestled in about 110 feet off the coast of St. Matin, remains largely in tact. The wreck sank unintentionally, and is one of the older wrecks on the island.

The wreck hosts a variety of marine life including garden eels, moray eels, rays, and a mix of coral.

Diving the wreck on my rebreather allowed me a dive time of just over an hour with only a short deco time of 20 minutes on the way to the surface. 

Additional resources

For diving in St. Martin, I have used both of these operations, which have supported rebreather diving (and recreational open circuit). I do not receive anything in exchange for recommending them, and I found them to both be great dive centers.

Ocean Explorers Dive Center in Simpson bay

Dive Sint Maarten in Philipsburg


Picture of Josh


Josh is an optical technician and owner of See the Sea RX. He is a PADI instructor and rebreather diver- he has been involved in diving for more than 20 years. He has also worked as a sergeant at the Harris County, Texas, Sheriff's Office, which included time as the instructor for the dive team. Josh also holds a masters degree in data analytics from Texas A&M.