With so much marketing and so many attractive options that feature waterproof,  how to choose the best waterproof bag or case is tricky business.

The thing is, waterproof is one of those features about the bags and cases that we buy that almost always requires some “special investigation” to get to the bottom line.

• “Is that fabric really waterproof?
• “How can a tote be totally waterproof if it is sewn together at the seams?”
• "Is a roll top waterproof backpack better than a duffel with a waterproof zipper?"

1. Your “Most Often Use”
   1. The Commuter
   2. The Recreator
   3. The Professional
2. The IP Code
3. Critical Construction Features
   1. The Fabric or Material
   2. Integrity at the Seams
   3. The Closure System

When you are selecting a dry bag or a waterproof case there are two big-picture concerns to sort through. The first is your Most Often Use.  Your second concern should be about 3 Critical Construction Features.

Your Most Often Use

Which of 3 different profiles describes how you use your waterproof gear? Are you The Commuter? Are you The Recreator?  Or, are you The Professional ?

The Commuter

The Commuter is the guy or gal that uses a carryall to protect valuables from wind, dust, snow or rain. That means your most often use is to shelter your stuff when the weather is inclement.

Technically speaking, The Commuter is looking to prevent the ingress of water for a short period of time. That would be, as long as it takes to find cover from the rain, sleet, or snow.
Runners, walkers, bicycle or railway commuters, and trail sports folks are all great examples.
 
When a downpour becomes a “dunk”, or a “submersion”; that’s when The Commuter  needs the same kind of waterproof protection as The Recreator.

The Recreator

Next is the person who intentionally includes the water in their outdoor recreation.  You’re into water sports. Or, it’s the beach. Maybe you’re thinking about boating, a waterproof backpack for jet skiing, a dry bag for kayaking, or a waterproof cell phone case that floats. 

The Recreator  needs gear that offers protection from a constant spray or powerful splashing, as well as a shallow submersion.

By the way, consider a “shallow submersion”  several inches to 4 feet underwater, for a few seconds or more.  

THE PROFESSIONAL

Finally, there is The Professional profile.  These are folks who carry valuables into challenging environments or extreme conditions.

Generally, those conditions involve total submersion or significant water pressure for an extended period of time.

A few examples are scuba and deep water divers, law enforcement and emergency personnel, or folks who need to keep their ammunition dry while they are duck hunting.  

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Your most often use should guide you as you answer “How much waterproof protection is enough for Me ?”.

So, it's obvious that everybody needs to protect belongings from water, at some point. Water-resistant bags and cases are sufficient for lots of folks in The Commuter profile.  For others, totally waterproof  is a necessity.

The IP Code

 

3 Critical Construction Features

Material    -   The fabric or material with which the product is made.
Seams         -    Integrity at the seams, handles and fixtures.
Closure      -    How effective is the closure mechanism.


  
 

 The Material 

 

THE SEAMS

 

The technique that is used to hold aN Item together at the seams is the feature that distinguishes bags and cases suitable for The Recreator.

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A totally waterproof container is a Pack, A Duffel, or a case that combines impenetrable material and integrity at the seams with a leak-proof closure system.

1. Gaskets & Clamps
2. Zippers
3. Zip Seals
4. Roll Tops

GASKETS & clamps

Most hard cases use rubber or silicone gaskets and a clamp mechanism in order to create a seal. Look for an IP Code and let it be your guide. 

Zippers

To start, we should acknowledge that zippers are the most common system for closing bags, backpacks, duffels and cases.

Second, let’s note that a zipper is a fastener that draws together, or “attaches” two ends.  But the mechanism was not conceived as a device that would create a “seal”.

A common zipper, without significant modification, does not provide a lot of waterproof protection. Heavy rain or splashed water infiltrates the elements of a coil zipper easily. 

So designers frequently cover a common coil zipper with a flap. That feature offers The Commuter water resistant protection.

A Reverse Coil zipper is another solution that can work for The Commuter. These are modified coil zippers that are also categorized as water resistant.

Next is zippers that are waterproof.  Most waterproof zippers are molded thermoplastics. They are far more effective as a defense against the water pressure that comes with powerful splashing or shallow submersions.

Better quality waterproof zippers are welded to a thermoplastic waterproof material.  That combination renders a waterproof bag that is appropriate for The Recreator. 

Finally, we have airtight zippers systems. Originally, these mechanisms were designed to maintain air pressure within a space suit. Since then airtight zippers have been adapted for use on deep sea drysuits, heavy duty and industrial grade waterproof gear. 

Get More:  5 Things to know About Waterproof Zippers 

ZIP Seals

Another common closure system is zip seals.   Zip seals are used a lot on waterproof cell phone bags and a variety of duffles.

One key feature to look for in a zip seal system is “long and straight”. That’s because bends and turns can challenge the effectiveness of a zip seal. 

Also, they are vulnerable to burst pressure. That is a tendency to open from the inside out when the external pressure becomes too much.

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THE MOST EFFECTIVE MECHANISM FOR CLOSING A WATERPROOF BAG IS A ROLL TOP. 
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Roll Top

Personally, I still find it to be amazing, mostly because by 2018 you’d think that innovating designers would have offered something new. But, the simple truth is the roll-top system remains the most reliable waterproof closure system.