Sure It’s Waterproof . . . I Think
Can your new handheld GPS pass the deep-water test?

As a sailor I’d love to be able to claim that the first time I really worried about the waterproof rating of my boat’s electronics was while doubling the Horn or some other such salty endeavor. Instead it occurred during the “Pearl Harbor Dinghy Wars” of ’93, when my neighbor Phil tacked through a steady barrage of water balloons to lob a watery grenade into my cockpit—and squarely on top of my new handheld VHF radio. After issuing the appropriate curses and hand gestures, I quickly wiped it down, and then consulted the owner’s manual to determine its chances of surviving such a dousing. Unfortunately, I couldn’t make heads or tails of what the manufacturer was trying to tell me.

You’d think a term like “waterproof” would be fairly straightforward. It’s not. “Waterproof,” “submersible,” “splash-proof,” “drip-resistant,” “watertight”—they’re all ambiguous terms and downright worthless unless applied to a recognized standard. There are numerous, quantifiable standards that manufacturers can use to accurately rate how environmentally sealed their products are, but not all are universally known or accepted, and some manufacturers even develop their own. 

The other half of the problem is the applicability of the ratings themselves to “real world” conditions. If you look at the specifications for a piece of gear, you’ll occasionally see a manufacturer provide easy-to-visualize statements like “this product can be submerged for a period of 1 hour at a depth of 2 static feet of clear water.” What consumers are more likely to see, however, are waterproof ratings like “USCG CFR 46,” “IP56,” or maybe even “JIS6.” What exactly do they mean? 

To me, waterproof means something can emerge unscathed after being dropped into 10 feet of water and left there for the hour or so it takes to dig out my dive gear and find it. A manufacturer, on the other hand, can contend that a waterproof gadget need only survive a flash dunking in the dinghy’s bilge or the moisture from an operator’s sweaty fingers. Before laying out the big bucks for that new electronic gizmo, you may want to familiarize yourself with the ratings manufacturers use to establish their waterproof credentials. Here are the four you’re most likely to encounter and what information they do (and don’t) provide.   


Some manufacturers, such as Raymarine and Apelco, simply cite USCG 46 CFR as proof of how environmentally robust their equipment is, a practice that leaves most consumers scratching their heads. The Code of Federal Regulations (CFR) is a massive, multiple-volumed collection of rules representing broad areas subject to federal regulations. Its 50 titles are divided into chapters normally bearing the name of the federal agency responsible for them, thus USCG 46 CFR denotes Title 46 of the CFR, which is issued by the U.S. Coast Guard.

Finding a specific rule in the CFR involves a bit of work, to put it mildly, and if the rule is not cited by volume, title, part and section, be prepared for a heavy dose of annoyance and frustration. Further complicating the matter is the fact that each volume of the CFR is upgraded annually, and these changes may or may not be reflected in a manufacturers’ claims.

I recently called Raymarine to find out exactly what the company meant by listing USCG 46 CFR on the spec sheets for its radar units and where to find it. Each department I was shuffled to chanted the same mantra: “It’s in 46 CFR. We don’t know exactly where, but it’s in there.” I finally got someone to say it was in section 110.15, and that it defined a waterproof machine as one in which “a stream of water from a hose with a nozzle one inch in diameter that delivers at least 65 gallons per minute can be played on the machine from any direction from a distance of about 10 feet for a period of not less than
5 minutes without leakage.”

Unfortunately, this language is from an outdated 46 CFR edition, which was revised in 2000. The new section 110.15 states something else entirely—and in fact seems to pass the buck. It says that “waterproof” means enclosed in such a way that equipment meets either National Electrical Manufacturers Association standards or the new European Community Specifications, neither of which are spelled out in the CFR tome. I called the manufacturer back to see if the company, by referring to 46 CFR, was saying its product met the newer definition, and I was given the telephone equivalent of a shoulder shrug.

In chapter 175.400 of the current 46 CFR (which deals with Coast Guard inspected small passenger vessels) I did find language similar to that in the old paragraph 110.15, but it used the term “watertight,” not “waterproof.” Does the word “watertight” indicate more or less protection than the “waterproof” listed in the old and new 110.15? No one I spoke to at Raymarine knew the answer. Even if the terms are interchangeable, how does spraying equipment with a hose correlate to real world conditions anyway, where gear is more likely to be drenched in varying depths of salt water?

After hours spent trying to answer the above questions, I finally concluded that it doesn’t really matter, as neither the new paragraph 175.400 or the old paragraph 110.15 are a standard or even a requirement—they’re simply the Coast Guard’s definition of waterproof. What really matters is that as a manufacturer, simply listing “USCG 46 CFR” as a waterproofing standard is a vague declaration at best and a decidedly lame practice at worst, especially when the idea here is to give customers information they can actually use at the showroom when deciding which gear to buy. fortunately, many marine manufacturers are beginning to use much more specific standards published by the Japanese Standards Association, the International Electrotechnical Commission and the National (U.S.) Electrical Manufacturers Association. These ratings are far more informative, provided you’ve familiarized yourself with their ratings system beforehand.

JIS Scale 

Some companies—ICOM America, for instance—use the very specific Japanese Industrial Standards (JIS). The Japanese standards are used all over the world by commercial and governmental organizations involved in equipment design and manufacturing, quality assurance, construction, testing, and maintenance. The standards cover an extremely wide range of industrial and mineral products and are classified into 17 divisions, ranging from civil and architectural, to electrical, automotive and shipbuilding. For waterproof ratings, JIS utilizes a 0 to 8 scale to rate “ingress protection.”
JIS Scale
JIS 0: No special protection.
JIS 1: (drip resistant 1): Vertically dripping water shall have no harmful effect.
JIS 2: (drip resistant 2): Dripping water at an angle up to 15 degrees from vertical shall have no harmful effect.
JIS 3: (rain resistant): Falling rain at an angle up to 60 degrees from vertical shall have no harmful effect.
JIS 4: (splash resistant): Splashing water from any direction shall have no harmful effect.
JIS 5: (jet resistant): Direct jetting water from any direction shall have no harmful effect.
JIS 6: (water tight): Direct jetting water from any direction shall not enter the enclosure.
JIS 7: (immersion resistant): Water shall not enter the enclosure when it is immersed in water under defined conditions.
JIS 8: (submersible): The equipment is usable for continuous submersion in water under specified pressure.
IEC 529 

Still other companies—Magellan, for example—use the International Electrotechnical Commission’s Publication 60529 (sometimes called simply IEC 529) of the European Community Specifications to rate how waterproof their products are. The IEC is a global organization that prepares and publishes national and international standards for electrical, electronic and related technologies. IEC 60529 uses a two-digit code (one number for solids, the other for liquids) to rate ingress protection provided by a device’s case or enclosure. On a scale of 1 to 8 (for liquids), the larger the number, the better the protection. In the code “IP56” for example, 5 describes the level of protection against solids, while 6 describes the level of protection against liquids. If a piece of gear is not rated for protection against both, an “X” is substituted for the one not rated. Thus, a rating of IPX6 would mean the equipment has a liquid protection rating of 6, but is not rated for protection against solids (principally dust).
IEC Ratings 
First Number (solids)
0: No protection.
1: Protected against solid objects up to 50 millimeters.
2: Protected against solid objects up to 12 millimeters.
3: Protected against solid objects up to 2.5 millimeters.
4: Protected against solid objects up to 1 millimeters.
5: Protected against dust, limited ingress (no harmful deposit).
6: Totally protected against dust.
Second Number (liquids) 
0: No protection
1: Protection against vertically falling drops of water.
2: Protection against direct sprays of water up to 15 degrees from vertical.
3: Protection against direct sprays of water up to 60 degrees from vertical.
4: Protection against water sprayed from all directions, limited ingress permitted.
5: Protected against low pressure jets of water from all directions, limited ingress permitted.
6: Protected against low pressure jets of water, limited ingress permitted.
7: Protected against the effect of immersion between 15 centimeters and 1 meter.
8: Protected against long periods of immersion under pressure.

Occasionally you’ll see NEMA referenced on spec sheets. Established in 1926, NEMA promotes safety in the manufacture and use of electrical products and acts as an industry representative in new and developing technologies.
NEMA Standard 250 deals with enclosures designed to protect people from accidental exposure to stray electricity and to protect equipment from accidental exposure to destructive elements like dust and water. A list of 13 “Types” moves from protection against falling dirt (Type 1) to protection against seepage (Type 13); for some reason there are no Types 7 to 11.
NEMA Ratings 
(for Liquids) 
Type 2: dripping and light splashing of liquids (indoor use).
Types 3, 3R, 3S: falling rain, sleet, snow, and the exterior formation of ice.
Types 4, 4X: falling rain, sleet, snow, splashing water, hose-directed water and the exterior formation of ice.
Types 5, 12, 12X: dripping and light splashing of liquids (indoor and outdoor use).
Types 6, 6P: hose-directed water, temporary and prolonged submersion at a limited depth, and the exterior formation of ice.
Type 13: spraying, splashing and seepage of water, oil and non-corrosive coolants (indoor use).

In a perfect world, all equipment ratings would be issued under a single, universally accepted standard that allowed quick, easy comparisons and categories everyone could understand and interpret. Until that happy day, a little research and comparison shopping is a buyer’s best defense against getting soaked when purchasing that new piece of gear.

Frank Lanier is an FCC licensed electronics technician and owner of Captain F.K. Lanier & Associates, LLC, Marine Surveyors & Consultants of Chesapeake, Va.