Here's a quick guide to all those standards:
1) waterproof - may withstand a heavy dew. Meaningless without a standard to apply to it.
2) IP ?? - the "Ingress Protection" rating. IP Code Often you will see these quoted as IP67 or something similar. This is a solid standard if the manufacturer is quoting it, but make sure the rating is high enough for what you need.
The first digit is resistance to solid particles like fingers, marbles or dust getting in the equipment. If the first digit is an X it means 'we didn't test for solid objects or we don't care' Not very applicable to sailors.
The second digit relates to how water resistant the item is. These include:
IP X5 - gently wetting it down with a garden hose. Might be ok for something you keep inside but forget about real world water resistance in a cockpit.
You want IP X6 as a minimum. This is "Water projected in powerful jets (12.5 mm nozzle) against the enclosure from any direction shall have no harmful effects. Test duration: at least 3 minutes
Water volume: 100 litres per minute. Pressure: 100 kPa at distance of 3 m". So basically blasting it with a powerful hose from 3m away.
IP X7 - immersion up to 1m for 30 minutes. For a handheld VHF that might get dunked in the bottom of a dinghy this might be a good standard to look for
IP X8 - depths > 1m. Usually specified by manufacturer. Not very common in recreational marine equipment but quite good if you can get it.
3) CFR - this usually is a reference to the US Code of Federal Regulation. CFR 46 is a huge volume so just saying 'meets CFR 46' is very vague. Raymarine is bad at using this as a specification though their newer equipment is starting to use IP X6 (displays and instruments). Their current VHF say IPX7 (submersible) - anybody want to try?
46 CFR 110.15 gives a few definitions
Waterproof means watertight; except that, moisture within or leakage into the enclosure is allowed if it does not interfere with the operation of the equipment enclosed. In the case of a generator or motor enclosure, waterproof means watertight; except that, leakage around the shaft may occur if the leakage is prevented from entering the oil reservoir and the enclosure provides for automatic drainage.
Watertight means enclosed so that equipment meets at least a NEMA 250 Type 4 or 4X or an IEC 60529 IP 56 rating
So just saying CFR 46 doesn't really say anything unless you say 'waterproof to CFR 46' or similar language.
5) JIS - A Japanese standard that ICOM uses frequently
|JIS "4"||Splashing water from any direction shall have no harmful effect (Splash resistant)|
|JIS "5"||Direct jetting water from any direction shall have no harmful effect (Jet resistant)|
|JIS "6"||Direct jetting water from any direction shall not enter the enclosure (Water tight)|
|JIS "7"||Water shall not enter the enclosure when it is immersed in water under defined conditions (Immersion resistant)|
Again - JIS 4 is hopeless if you want to keep the water out. JIS 5 is a bare minimum.
Here's a good object lesson:
Cobra Handheld VHF
- 100% waterproof (JIS-4)
But it's not waterproof as you or I understand it. It's splash proof. IIS-4 is a very low standard as you can see above.