On the Mark Scuba, LLC

05/02/2026

Just letting everyone know the Scuba and Hydro shop will be close til Thursday 7th. Have to get away on a mini Vacation to the Caribbean.

03/09/2026

02/26/2026

Dive season is approaching, and the weather will start warming up, along with water temperatures, so it is essential to avoid last-minute equipment checks, only to discover that your cylinders require hydrostatic testing, visual inspection, and refilling with air or nitrox, which can lead to a rushed search for a service shop. We recommend bringing your cylinders to our facility, where we can provide comprehensive services, including hydrostatic testing. Additionally, do not forget to bring in your regulators, BCDs, and other equipment for their annual inspections and maintenance.

02/03/2026

Like for everyone to say a Prayer for our friends and family over at Smoky Mountain Divers. Zac Burton had a medical emergency this weekend and was placed in ICU and is now off the ventilator and talking. The dive community is a close knit group of ppl and we all share the same passion for scuba diving.

01/01/2026

Happy New Year 2026!
🎉🤿
Thank you for being part of the On the Mark Scuba, LLC family. Here’s to another year of safe dives, new skills, and unforgettable underwater adventures. We can’t wait to dive into 2026 with you!

12/23/2025

Can’t make it during business hours give us a call or txt we will make it happen! We have been known to open early or stay later to meet the customers needs!

12/23/2025

⏰🎄 24–48 HOURS LEFT FOR CHRISTMAS STOCKING STUFFERS! 🎄⏰
Still finishing up your Christmas shopping? We’ve got last-minute gifts that divers (and future divers!) will actually use.
🎁 Stocking Stuffer & Small Gift Favorites:
🔦 Dive flashlights
📣 Whistles
📝 Slate boards
🔪 Z-knives & ✂️ trauma shears
📓 Rite in the Rain notepads
🧰 Travel tool kits
🚩 DSMBs & spools
🎒 Regulator bags & gear bags
🤿 Kids mask & snorkel combos
🎟️ On the Mark Scuba Gift Cards — always a perfect fit!
Need something bigger? We also have a wide variety of stocked gear in-store including:
🤿 Regulators • BCDs • Fins • Booties • Masks • Snorkels • and more!
📍 Last-Minute Shopping Hours:
🕙 Tuesday & Wednesday | 10:00 AM – 7:00 PM
Inventory is moving fast—once it’s gone, it’s gone!
🎅 Stop by On the Mark Scuba and wrap up Christmas the easy way.

Send a message to learn more

12/12/2025

Still need some gift ideas this holiday season? Our season passes are on sale now until the end of the year for $250.00! This pass covers all divers living in the same home making it a great family gift option. It will cover your daily fees until the end of 20206. Its going to be dive season again before you know it!

12/11/2025

🔧 Why Hydrostatic, Visual, and Eddy Current Testing Matter — Especially for Older 6351 Alloy Cylinders.

The photos below are from a cylinder neck I inspected recently. At first glance, the threads look clean and normal — but with older aluminum cylinders, especially those made from Luxfer’s or Walter Kiddie 6351-T6 alloy, what you can’t see is what matters most.

This is the exact area where Sustained Load Cracking (SLC) begins. These cracks start microscopically at the base of the threads and are not visible during a basic visual inspection.

⚠ Why These Cylinders Require Special Testing
• SLC initiates deep in the metal at high-stress points in the threads.
• Visual inspection alone is not enough to detect early cracking.
• Eddy current testing must be performed at every annual Visual Inspection for cylinders made from 6351 alloy.
• Eddy current equipment can detect flaws 2.5–5.0 mm deep into the aluminum, far beyond what the eye—or even magnification—can see.
• Hydrostatic testing confirms overall structural integrity, but only eddy current testing reveals early thread-root cracking.

💰 The Reality: Sometimes It's Cheaper to Retire
For cylinders that are 30–40+ years old—especially 6351-alloy tanks—it often becomes more cost-effective to retire them than to keep paying for:
• Annual VIP + eddy current
• Hydrostatic testing
• Valve rebuilds
• Recurrent cleaning/tumbling
By the time a cylinder has reached this age, replacement is typically safer, cheaper, and more reliable.

✔ What Every Diver Should Do
• Check your tank’s manufacture date and alloy stampings.
• Ensure every annual VIP includes eddy current testing on 6351-alloy cylinders.
• Hydrostatic testing is required every 5 years, with the exception on a star rated (storage) cylinder and they can be extended to 10 years.
• If a cylinder is questionable—or simply old—retire it. Dive gear is replaceable. Your safety isn't.

If you need help identifying your tank alloy, interpreting markings, or scheduling proper inspection, On the Mark Hydro Testing and Inspections here to help. Stay safe, stay informed, and dive smart. 🥽🌊

We are a one stop shop! Shop for new gear, sign up for classes, get your gear inspected and updated for the up coming season and get your cylinders serviced all at the same shop!

11/29/2025

Now is the time to buy!! Save time and get more dive time when you purchase a pass.

Hey divers! Its that time of year again to snag your season pass for the discounted price of 250.00. Starting this Friday through December 31st you can purchase the 2026 season pass. Prices go up beginning January 1st! Warmer weather will be back before you know it so be ready.

11/27/2025

From all of us at On the Mark Scuba, we wish you a very Happy Thanksgiving!
May your day be full of gratitude, great company, and memorable moments. Stay safe and enjoy the holiday! 🍂🦃

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