High and Dry
Written by PATRICK E. CLARKE
FROM BATTERIES TO BULLETS, WATERPROOF BAGS KEEP THINGS SHIP SHAPE.
If only the Skipper and Gilligan from the show “Gilligan’s Island” had some waterproof bags they could have preserved their radio and their ill-fated three-hour tour would have lasted just a few additional hours while rescuers came instead of the three years that the show ran.
The reality now is that rapid progress in the development of waterproof bags allows for the protection of everything from battery packs to combat trauma kits to pretty much every weapon that can be carried.
Eric Revels, founder of Asheville, N.C.- based Watershed Drybags, is one of the pioneers who have helped propel that rapid progress. Ten years ago, Revels was a river rafting guide who had a great idea. “The only waterproof bags at that time were known as roll-over bags because you put gear in them and rolled the bag flaps over several times. They weren’t really completely submersible,” said Revels. He started a company with truly submersible bags and his target audience was the paddle sports market.
Soon, his company also began providing waterproof bags to special forces units. The naval special warfare mission in particular requires each operator to function almost exclusively in a maritime environment—an environment that is especially harsh on sensitive equipment.
The goal is to produce a set of reliable, waterproof dive bags designed for military use, which can be submerged to a depth of 66 feet without leaking, according to USSOCOM representatives. “For general purposes, our definition of submersible is a product that is waterproof to 66 feet of sea water for three hours duration, but that may be changed based on the individual items requirements for use,” said the USSOCOM representative.
Currently, NSW units purchase their own bags, based on operation needs. “There’s a five-year life cycle on our products,” said Revels. “We’ve been supplying special ops units for over five years and haven’t had anything come back to us.”
A typical recreational user puts things into a bag and keeps them zipped until they get to a campsite, according to Revels. “Military guys access their bags more often so the opening-closing method had to be more user-friendly.”
Revels developed and patented a heavy duty ziplock extrusion for his bags, making for a zipdry closure system. “You open and close it like a ziplock bag,” said Revels. Watershed Drybags also uses a thermoplastic material known as polyurethane and welds their seams via radio frequency. “Once welded, it’s stronger than the original material,” said Revels. Their bags have been tested to nine atmospheres, or approximately 300 feet, which Revels points out, “Was the cracking depth for the weapon—but it was still protected by our bag.”
“If the bag can keep out water, especially at pressure, then it can keep out the damaging sand and grit the troops are facing today,” said the USSOCOM representative. He continued, “In that environment, an optic lens tends to get dusty, which makes frequent cleaning necessary, and can eventually scratch lenses. Sand can ruin other sensitive items and equipment special operations forces carry in the field—waterproof/sandproof bags then become a priority.”
Many of the waterproof bags in the Watershed Drybags line were created to carry specialized military equipment. “Our most specialized bag is a waterproof power pack,” said Revels. “It’s an array of six BA-5590 batteries linked together along with a waterproof power outlet that can be used underwater or buried in the desert.”
One of the most significant challenges in any waterproof bag system is ensuring the closure system remains operable in all conditions, dry or wet, hot or cold, while keeping out other elements, such as sand and dirt, which can interfere with the closure mechanism, according to the USSOCOM representative. “For example, developers want to know how much sand or grit it will take to render the closures inoperable, or at what temperature does the material become nonpliable. Developers also want to ensure that the bags are safe to operate in all environments in which our special operations forces may find themselves, from the heat of the desert to marine environments.” He added that another concern is ensuring the bags are somewhat user-friendly, and that users can be easily trained to use the bags properly.
The government contractor that had the battery bag contract chose Watershed because it was already in use with the special ops community and all they had to do was create the necessary modifications for the battery-specific use. Most importantly was an external connector which was designed using marine brass and urethane. After four generations of the connector design, a bag was finalized that weighed only 2.2 pounds, the same weight as a single BA-5590.
The bag has creative carry handles plus has an oral inflation tube that can be used to adjust the buoyancy of the bag as needed. Additionally, if, for some reason, the battery vents, the gas is captured by the bag and held until it can be safely released.
Of course, Watershed Drybags isn’t the only company providing waterproof bags to military personnel. U.S.I.A.
U.S.I.A. has been supplying waterproof bags and dry suits to the U.S. military since 1989, according to Kim Johns, director, Military Defense Division, located in St. Helens, Ore. “We’ve been under GSA contract since 2000 and U.S.I.A. bags are currently used by U.S. Army Special Forces, U.S. Navy SEALS, USAF pararescue and special tactics units and U.S. Marine raid and reconnaissance units.”
Johns also makes reference to a 1997 “Evaluation of Waterproof Bags for Special Operations Forces.” Waterproof bags from various companies were rated in categories such as: puncture resistance; pinch resistance; seam strength; tear resistance; abrasion resistance; zipper operation; handling on land; finish suitability and buoyancy control, among others. The study found that “The U.S.I.A. bags are recommended as the future bags for SOF procurements.”
Johns also explained some terms. “Puncture resistant refers to an object applying pressure to one specific are which could create a ‘single hole’. Tear resistance refers to the failure of a fabric which results in the fibers giving away to create separation of the entire piece.”
Abrasion resistance is a method of testing [abrasion] in which the fabric would be subjected to a surface much like that of a belt sander in which the revolutions would be calculated to determine resistance before a hole developed, according to Johns. “The finished suitability is the product as it stands after being inspected out of the box,” said Johns.
Understanding the difference between water resistant, water repellent and waterproof is the most challenging aspect in the development of bags that are truly waterproof in design, according to Johns. The U.S.I.A. definition of waterproofing is “manufacturing a bag which can maintain waterproof integrity in 132 feet of sea water as well as being adaptable to various other military systems with specific attachment hardware.”
U.S.I.A. has designed and manufactured over 40 different specialty waterproof bags for the U.S. military, according to Johns. He specifically mentions the combat trauma bag, which was designed for Navy SEAL medics. The bag has Velcro interior sides for holding several smaller pouches for equipment and supplies. Pouches have clear window fronts to allow medics to quickly determine and access the proper supplies.
“Our CBR [chemical, biological and radiological] bag was designed for the current issue gear used from CBR attacks,” said Johns. “U.S.I.A. manufactured over 50,000 of these bags at the beginning of the Iraq war for protection of gear issued to U.S. forces.
U.S.I.A. also has designed and manufactured the M.A.N.T.A. [Maritime Adjustable Neutral Transit Assembly Bag] for Air Force pararescuemen. “The M.A.N.T.A. has a builtin weight system for ‘combat swimming,’ which can be instantly ejected in case of emergency,” explained Johns.
DIVING UNLIMITED INTERNATIONAL
Meanwhile, Diving Unlimited International Inc. (DUI), with U.S. operations based in San Diego, Calif., has been working with, and providing products for, the U.S. military since Dick Long founded the company in 1963.
DUI waterproof bags have been purchased by U.S. Navy SEALS, U.S. Marine Corps Reconnaissance, U.S Army Special Forces, U. S. Air Force combat controllers and pararescue teams, in addition to several friendly foreign militaries, according to Carol Heaton, DUI’s government sales manager.
“DUI received a contract from the U.S. Marine Corps in 2005 for its Scout Swimmer Assault Pack,” said Heaton. “This bag was selected by the Marines after their own competitive trials using four different manufacturers’ versions of the bag. The result was that they purchased 1,993 of those bags.”
DUI offers a waterproof bag that protects the PSC-5 radio. Made from DUI’s tough trilaminate material the top of the bag incorporates a vinyl-viewing window to see or show frequencies. A layer of trilaminate material covers the window so it is only accessed when needed.
As to the toughness of trilaminate material, Heaton explains that some waterproof bags are made of trilaminate material while some are made of bilaminate material. The seam construction used on trilaminate (three-layer) waterproof bags is known for its strength and durability. To insure waterproof seams, they are coated with three layers of a hand-applied urethane that completely penetrates all layers of the fabric seams and thread. The coating is very flexible and will not peel or crack even under extreme cold or heat conditions. If there were to be a seam leak it can be easily repaired at the field level, which consists of reapplying a small amount of the urethane coating, according to DUI.
Bilaminate (two-layer) manufacturing technique usually consists of a urethane heat tape applied over seams to create a waterproof seam.
Heat taped seams can be prone to peeling or cracking, especially when exposed to high heat or cold.
Bilaminate material has also been known to delaminate—which is the separation of the outer nylon from the inner polyurethane coating.
Simply put, DUI uses trilaminate on all of their bags.
THE FUTURE
As for the future of submersible products, SOCCOM does have a wish list. According to the USSOCOM representative, “As technology evolves, we hope to see the following:
• Lighter materials, stronger tensile strength, visible see thru panels.
• Smart bags—with the outside of the bag functioning as a solar power cell that can that can power the radio within, or recharge batteries. Another possibility would be to develop a bag that can also serve as an antenna.
• A rucksack that is completely waterproof, modular and compartmentalized, able to withstand the rigors of combat and day-today use.
• A shoot-thru weapons bag that is user serviceable, and can be reused with user-level field maintenance.
It seems that there will be plenty of challenges ahead for the waterproof bag community.
And if the Professor ever gets off “Gilligan’s Island”, perhaps he can help. ♦