Safety Survival Whistle with Nylon Bolt Snap

Name: Safety Survival Whistle with Nylon Bolt Snap
Brand: Oceans Optics
SKU: 4000153033048-1 Piece
Price: 8.00 USD
Availability: InStock

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Quantity

$8.00 USD

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Shipped with Care. No Hidden Fees. Just Clear Vision Ahead.

Product Description

Designed for those who crave both clarity and adventure, the RX Carbon Dive Mask offers precision vision and ultimate comfort for every dive. With RX-ready lenses, it’s easy to customize for crystal-clear underwater vision, whether you’re nearsighted or farsighted.

This mask is ideal for adventurers looking to document their underwater experience. The built-in action camera mount allows you to attach your GoPro or other action cameras, so you can effortlessly capture every breathtaking moment. Perfect for travel vloggers, underwater photographers, or anyone wanting to relive their dives with precision.

The elastic headband provides a comfortable, tangle-free fit, keeping your hair out of the way, while the silicone skirt ensures a secure, leak-proof seal no matter your face shape. Plus, the quick-release strap lets you easily adjust your fit, making it perfect for on-the-go dives.

Mask Sizing Chart

How to measure your face for a prescription mask (width & height)

Rx Action (Large)

Size Category: Large — roomy fit for broader/longer faces.

How to measure

1Width: straight line from outer eye corner to outer eye corner (don’t wrap).
2Height: from just under your nose to just above your eyebrow line.

Mask Size Ranges

	Min (in)	Max (in)
Width	4⅛ ″	5¼ ″
Height	3¼ ″	4½ ″

Options: Nearsighted (−1.00 to −9.00) · Farsighted (+1.00 to +5.00) · Skirt: Black · Frame: Black · Integrated action-camera mount.

Free Shipping Canada & US

Orders $70+ ship free. Every order is carefully packed with quality guaranteed. Fast, trackable delivery in 3–10 days.

30 Day Return Policy

No returns on Whistles. Sorry it's just gross.

Free E-guide with every purchase

Snorkelling 101: Your Ultimate Guide to Better Aquatic Adventures

Now free with every order! Access your eGuide instantly after checkout or via email, and dive in at your own leisure.

View full details

Let customers speak for us

from 1229 reviews

Oceans Optics is the Best!!!

Oceans Optics is the BEST!!!

Gerald C.S.

Oceans Optics

07/18/2026

This mask has been incredible! It has re-given me back full HD Scuba Diving.

This mask has been incredible! It has re-given me my full joy of Scuba Diving as I can once again see things fully clear. The mask is wonderful and the price is outstanding. This is the ONLY place I'd ever order a vision mask from. I ordered one from Prescription Dive Masks and I would never use them again, as the Oceans Optics mask is way better for a much better price. I can't rave enough about how great this mask is and how glad I am to have purchased it.

Gerald C.S.

Rx Obsidian Farsighted Prescription Snorkel & Scuba Dive Mask

07/18/2026

Great

Anonymous

Oceans Optics

07/17/2026

Great! Quick shipping and accurate Rx

They’re great! I don’t use contacts and have poor eyesight - but with these it’s easy to see clearly underwater. Quick shipping and accurate Rx.

Anonymous

Rx Obsidian Nearsighted Prescription Snorkel & Scuba Dive Mask

07/17/2026

Easy shopping

Shopping for the prescription googles was easy and convenient.

Caren

Oceans Optics

07/08/2026

The prescription goggles: a game changer!

The prescription goggles were an absolute game changer during my snorkeling off the coast of Maui! As I am almost blind without my glasses I can see basically nothing with regular goggles, but with the prescription goggles I could see as if I was standing in front of an aquarium! The experience was out of this world!

Caren

Rx Obsidian Nearsighted Prescription Snorkel & Scuba Dive Mask

07/08/2026

Bought two sets of these prescription goggles for

Bought two sets of these prescription goggles for my 12 year old before her dive trip. They fit perfectly.

Vivian

Rx Obsidian Nearsighted Prescription Snorkel & Scuba Dive Mask

06/21/2026

Excellent company and customer service!

I really didn’t think I would be satisfied with this mask but after reading the reviews I figured I try it. I asked questions in my order and they were answered almost immediately. I received the mask and snorkel set very quickly. I’m thrilled I found this company and took a chance with them. You will be too.

Michele

Oceans Optics

06/15/2026

Amazing mask!!!

I haven’t used them yet. I will next week while in Bermuda. I was skeptical at first but after receiving them and trying them on I was amazed. So worth the cost which is very reasonable. Can wait to use them.

Michele

Rx Obsidian Nearsighted Prescription Snorkel & Scuba Dive Mask

06/15/2026

Great!!

Jmalcom

Rx Obsidian Nearsighted Prescription Snorkel & Scuba Dive Mask

06/05/2026

RX Elite Myopia Swimming Goggles with Anti-Fog Earplugs

Evelyn M.

RX Elite Myopia Swimming Goggles with Anti-Fog Earplugs

05/28/2026

The communication with the seller was excellent.
The glasses arrived within a week and a half.
Excellent glasses! The seller made one exactly as I told him to do.
And my daughter was really excited that she could see with them. She has it. The number is very high on the glasses and she can't see at all.
I highly, highly recommend it. The price is excellent and the service is outstanding!! !

Camila S.

Rx Optical Prescription Swim Goggles with Anti-fog & UV protection

05/27/2026

OBSESSED it’s so nice to be able to see underwater

OBSESSED it’s so nice to be able to see underwater. Thank you guys for making an excellent and affordable product! Can’t wait for future vacations

Deanna R.

Rx Lumix Nearsighted Prescription Scuba Dive Mask Aluminum

05/24/2026

RX Elite Myopia Swimming Goggles with Anti-Fog Earplugs

Vanetta S.

RX Elite Myopia Swimming Goggles with Anti-Fog Earplugs

05/22/2026

RX Elite Myopia Swimming Goggles with Anti-Fog Earplugs

Sharyn N.

RX Elite Myopia Swimming Goggles with Anti-Fog Earplugs

05/21/2026

What customers think about the store

Specializes in prescription swim/snorkel gear with custom lens options. Fast shipping, responsive customer service, and helpful guidance on prescription selection. Products include masks, goggles, and snorkeling accessories at reasonable prices. Customers prai...

AI-generated from customer reviews.

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Frequently Asked Questions

What is the difference between nearsighted and farsighted lenses?

Nearsighted (Myopia) lenses: Negative SPH values (example: -2.50) to help you see clearly at distance.

Farsighted (Hyperopia) lenses: Positive SPH values (example: +2.50) to help with close-up vision.

How do I find the sphere (SPH) value on my prescription?

Look for the column labelled SPH or Sphere. It can also be labelled Power or PWR. A minus sign (-) is nearsighted. A plus sign (+) is farsighted.

How should I adjust my prescription for clear vision underwater?

Underwater adjustment: For most people, choosing a lens that is 0.50 diopters weaker (towards zero) than your normal SPH gives the best comfort and clarity underwater.

Why: Water creates natural magnification, and mask lenses sit further from your eyes than glasses. Reducing by 0.50 helps keep vision feeling natural and comfortable underwater.

Examples: If your SPH is -2.25, choose -2.00. If your SPH is -2.75, choose -2.50.

Our lenses are available in 0.50 increments, so choose the closest available option.

I have astigmatism (CYL). What should I choose?

Our lenses are sphere only, meaning they correct SPH but not CYL directly. You can still see a significant improvement. Use your SPH for each eye, then adjust based on your CYL value and sign.

Important: The + or − sign on your CYL matters. Check your prescription slip for the sign next to your CYL value.

Nearsighted (Minus −) lenses

CYL 0.00 to 0.75: Go 0.50 weaker than your SPH (closer to zero). The CYL sign has little impact at this level.
CYL 1.00 to 1.75 with minus CYL (−): Stay close to your SPH. You can go up to 0.50 stronger (further from zero) or up to 0.50 weaker (closer to zero).
CYL 1.00 to 1.75 with plus CYL (+): Stay close to your SPH. You can go up to 0.50 weaker (closer to zero) or stay at SPH.
CYL 2.00 to 3.00 with minus CYL (−): Stay exactly at your SPH. Only go 0.50 stronger if you specifically want sharper detail.
CYL 2.00 to 3.00 with plus CYL (+): Stay exactly at your SPH. Do not go weaker.
CYL 3.25+ with minus CYL (−): Move slightly toward stronger correction, rounded to the nearest 0.50 step.
CYL 3.25+ with plus CYL (+): Move slightly toward weaker correction, rounded to the nearest 0.50 step.

Special case: If your SPH is −0.50 or −0.75 and CYL is 2.50 or higher, start at −1.00.

Farsighted (Plus +) lenses

Our farsighted lenses come in whole steps only: +1.00, +2.00, +3.00, +4.00, +5.00.

CYL 0.00 to 0.75: Round to the nearest whole number toward zero.
CYL 1.00 to 1.75 with minus CYL (−): Round to nearest whole number, or one step stronger for sharper detail.
CYL 1.00 to 1.75 with plus CYL (+): Round down to the nearest whole number.
CYL 2.00 to 3.00: Stay at your SPH rounded to the nearest whole number.
CYL 3.25+ with minus CYL (−): Move toward stronger correction, round to nearest whole number.
CYL 3.25+ with plus CYL (+): Move toward weaker correction, round to nearest whole number.

Special case: If your SPH is +0.50 or +0.75, start at +1.00 regardless of CYL.

Use our Underwater Lens Calculator for an instant recommendation, or see our full guide: Choosing prescription snorkel mask lenses with astigmatism.

If you are unsure, upload your prescription and we will check your selection for you.

I can't find my lens strength in the dropdown. What should I do?

The dropdown shows all strengths available for that specific mask. If your exact number is not listed, choose the closest available option using the guidance above.

If you want us to confirm the best match, upload your prescription on the product page or email us at info@oceansoptics.com.

Can I choose different lens strengths for each eye?

Yes. You can select different strengths for left and right eye. You can mix and match any combination available in the dropdown menu.

How do I upload my prescription during checkout?

On the product page you can optionally upload your prescription so we can check your selection before we build it. You can also leave a note in the cart, or email us at info@oceansoptics.com.

How do I stop my mask from fogging?

A simple method is the toothpaste trick. Rub a small amount of toothpaste on the inside of each lens using circular motions for a few minutes, then rinse thoroughly. Do this before your first use and repeat if needed.

Before each session, you can also use a tiny amount of baby shampoo or dish soap mixed with water. Rub a thin film on the inside of the lens, then lightly rinse so a fine layer remains.

Do you have a guide to help me use my mask properly?

Yes. Here is our Mask 101 guide: Open Mask 101 (PDF).

What happens if I accidentally choose the wrong lens strength?

Message us as soon as possible. If the order has not entered the build or shipping stage yet, we can usually update the lens selection.

Are your lenses safe for both snorkeling and scuba diving?

Yes. Our lenses are HD tempered glass and are suitable for snorkeling and scuba diving up to 100 ft (30 m).

How long does delivery take, and can I track my order?

Most orders arrive in 5 to 10 days, but we recommend allowing up to 14 days to be safe. You will receive a tracking number by email once your order ships.

What is your return or exchange policy for prescription masks?

Your satisfaction, guaranteed.
You have 30 days from delivery to request a return, as long as the item is unworn, unused, with tags, and in original packaging. For full details, visit our Return Policy.

Safety Survival Whistle with Nylon Bolt Snap

Product Description

Designed for those who crave both clarity and adventure, the RX Carbon Dive Mask offers precision vision and ultimate comfort for every dive. With RX-ready lenses, it’s easy to customize for crystal-clear underwater vision, whether you’re nearsighted or farsighted.

The elastic headband provides a comfortable, tangle-free fit, keeping your hair out of the way, while the silicone skirt ensures a secure, leak-proof seal no matter your face shape. Plus, the quick-release strap lets you easily adjust your fit, making it perfect for on-the-go dives.

Mask Sizing Chart

How to measure

Free Shipping Canada & US

Orders $70+ ship free. Every order is carefully packed with quality guaranteed. Fast, trackable delivery in 3–10 days.

30 Day Return Policy

Free E-guide with every purchase

Snorkelling 101: Your Ultimate Guide to Better Aquatic AdventuresNow free with every order! Access your eGuide instantly after checkout or via email, and dive in at your own leisure.

Let customers speak for us

What customers think about the store

AI-generated from customer reviews.

Frequently Asked Questions

Snorkelling 101: Your Ultimate Guide to Better Aquatic Adventures

Now free with every order! Access your eGuide instantly after checkout or via email, and dive in at your own leisure.