[desirableroasted]

Like Bakkels, I consider how traffic would probably move through the sector. I draw two parallel line that represent the likely corridor (and it could be sector wide, or fairly narrow. Depends on where), then plot a zig-zag up and down the corridor for several days.

Hydrophone checks at the turning points (because they effectively extend your range beyond the parallel lines), and then at the middle.

In bad weather, of course, hydrophone checks every hour or so.

Pisces, thanks for the link. I had that chart once, but had forgotten about it.