Skimmer design - neck diameter / length

[Delphinus]

See if you can get ahold of "Aquatic Systems Engineering: Devices and How They Function" by Pedo Ramon Escobal.

http://www.amazon.com/Aquatic-System.../dp/1888381108

Sadly, no longer in print but I remember from a few years ago it was reputed to be a bible with all sorts of theory behind good skimmer design.

I'd love to get my hands on a copy myself .. even a photocopy or something would do.

Not sure if it would answer your question though, but it might.

Good luck!