Lures - depth?

[Apollo]

Might be a dumb question, but I don't know the answer.

With lures, often they are rated at a depth eg 2m. I know there is some info on the packet regarding max speed and preferred speed range, but my question is what is the parameters for which the quoted depth is measured? To a degree, varying speed with affect depth, as will the amount of line let out. I was looking at a lure yesterday and it was rated at 1m with a preferred speed of 2-4kn and a max speed of 5kn. The way I saw it, even within the preferred lure speed range, one is twice as fast as the other and would have significant affect on the depth the lure travels.

I know other factors affect depth, such as line type, salinity levels, temp, etc

So - What is the standard that is used for classifying lure depths? line length and speed?

Thanks

[2manylures]

Although Rapala have a "standard" for casting & trolling which is covered in a pocket booklet using 10lb mono but once you change the diameter & retrieve speed {both in most situations} then everything is thrown out the window.

I only personally use manufacturers ratings as a very rough guide only & don't think you could use any as gospel unless they're floating surface lures.

You're dead right on the 2-4kn speed difference, a crock of s*** from the maker I would think.