IPX7 TEST, How deep

[H.G.Sun]

strictly speaking, to test of a light OK for IPX7, how deep under water should it be.

[Chloe]

IPX7 is up to 1m “temporary” immersion:

Understanding the IP (Ingress Protection) Ratings of iButton Data Loggers and...

Actually, the test is for 30 minutes:
http://www.ce-mag.com/archive/06/ARG/bisenius.htm

Ratings IPX7 and IPX8. Tests for the ratings IPX7 and IPX8 address the possibility of moisture ingress from submersion in water. For IPX7 testing, the sample is submerged for 30 minutes. The lowest point of the enclosure should be 1000 mm below the surface of the water, and the highest point at least 150 mm below the surface. For IPX8, the test time and submersion depth are according to the manufacturer’s specifications and must be marked on the product (for example, “submersible for up to 1 hour at a depth up to 2 meters”).