|The short answer is that all Amerace® kits are designed and manufactured to remain fully functional when submerged in water for their lifetime.
The longer answer is as follows:
Everything starts with the FAA Advisory Circular AC150/5345-26C "FAA SPECIFICATION FOR L-823 PLUG AND RECEPTACLE CABLE CONNECTORS"
It states that:
"3.3.4 Seal. A watertight seal shall be provided between the mated plug and receptacle and between the rubber and metal parts of the plug and receptacle."
It goes on to require specific dimensions for the interfaces of the plug and receptacle:
"3.4.1 General. Each plug and receptacle (cable connector), type, class, and style shall conform to the dimensions and construction requirements shown on the applicable figures in Appendix I of this specification."
It then goes on to require a specific test to prove that a connector is watertight:
"...each plug and receptacle being tested shall be mated and immersed in a tap water bath at room temperature, 20-25 °C. Immerse not more than 2 feet (0.6 m) of cable, 1 foot (0.3 m) of the plug, and 1 foot (0.3 m) of the receptacle. While immersed, each connector assembly shall be manually flexed for 2 minutes and then left immersed for a minimum of 24 hours with its cable leads flexed and maintained 180° from its longitudinal axis. Measure insulation resistance between conductors of each connected assembly after the 24 hour soaking period. The resistance measurements shall be taken 1 minute after a test voltage of 4.7 kV dc has been applied for 5 minutes to Type II connectors and 15 kV DC to Type I connectors. The minimum resistance between conductors shall be 25,000 megohms. Heat the tap water to 65 °C without removing the assemblies and maintain this temperature for at least 1 hour. Again measure the resistance between the conductor(s) and water, and between conductors with a 500-volt source. The minimum acceptable resistance after the heated soaking period shall be 10,000 megohms."
In essence, the FAA mandates certain dimensions for the interface, and uses an electrical test in water to confirm that the resulting connectors are watertight. These tests are made on individual samples, and it is extremely difficult if not impossible to extrapolate these readings to what a loop megger reading should be. The FAA considers 50 Megohms to be satisfactory for a new circuit, although some users request (and achieve) higher readings.
Naturally all Amerace® connectors meet the requirements of this specification, so by the FAA definition, they are watertight.
Amerace has never recommended additional protection against water (tape, heat shrink, or similar) - we accept conformance to the FAA specifications as evidence that FAA style connectors will provide satisfactory loops. We have also recognized that there is skepticism among some users about how watertight FAA connections are, and that is why in our Super kits we provided the AmerSeal for additional protection over the interface between connectors.