IP rating

The first digit rates protection against solids from 0 to 6, and an X means untested. The second rates water from 0 to 8. IPX4 means splash resistant from any direction, which covers rain. IPX7 means it survives thirty minutes under a metre of water. IP67 means fully dust tight and submersible.

For fishing, IPX4 is the practical minimum since rain is a certainty. IPX7 or better is worth having if you fish from a kayak or wade, because the lamp will eventually go in the water.

Ratings apply to the sealed product. A lamp with a removable battery door only holds its rating if the door is properly closed, and the seal degrades with age. Rubber gaskets dry out and crack, so an old lamp does not carry the rating it shipped with.

USB charging ports are the usual weak point on rechargeable lamps, since the cover over the port has to be seated correctly every time. Check it is closed before the lamp goes near water.