ECN Forum Forums Code Related Discussion NEC & other Code issues Liquid tight flex

Underwater is a wet location in regard to wiring methods. If you are talking about enclosures, you get into the NEMA rating, typically NEMA 6 for underwater.

The two places you see this the most, wiring for boat lifts and the wet niche pool light.

I see no reason why you couldn't use sealtite underwater, although not for that pool light. (not one of the specified wiring methods in 680.23(B)(2))

In fact it is one of the wiring methods in 553.7 and 682.13. 555.13(A)(1) says any chapter 3 wet location wiring method.
The NEC does not differentiate between a pond or the ocean.

"Underwater isn't above ground or direct burial??"

I was responding to Tesla's claim "Sealtite is only suitable for above ground and direct burial installations", which I didn't agree with.

Underwater is above ground unless it is buried on the bottom.

Again, we see that in boat lifts. The outboard lift plate will be wired under water most of the time and they try to actually get the raceway under the mud on the bottom if they can, for extra protection.

Next time I am out on the boat I will get you some pictures.

Do you realize that liquitite is Art. 350 in 2011 NEC and can be used in exposed or concealed locations.