Freighters vs. Sailboats

[Lodesman]

Originally Posted by psneeld

The real question is when you determine you are stand on or not. Because it's a judgment thing...because there are no numbers or absolutes are given in the COLREGS....and it's worded "risk of collision"...slight or large turns done far out are NOT in violation in the strictest sense and make GOOD sense. Most large vessels do this because they don't want to get into a close quarters situation.

You're right that colregs don't give specific ranges for when the rules kick in; for that you have to read a guide to the rules, such as the excellent one by Cockcroft and Lameijer - Guide to the Collision Avoidance Rules - A. N. Cockcroft, J. N. F. Lameijer - Google Books
This is the standard text that professional mariners around the world study.
They describe 4 stages of a collision scenario from the perspective of the stand on vessel. In the first stage, the vessels are far apart in time and/or distance - the steering and sailing rules do not yet apply, and both vessels are free to manoeuvre as they see fit.
In the second stage, the rules kick in - the stand on vessel shall hold its course and speed, and provide an adequate opportunity for the give way vessel to take the required action.
In the third stage, the rule 17.a(ii) allowance for the stand on vessel to manoeuvre if he feels the give way vessel is not acting, kicks in.
The fourth stage is where rule 17.b requires the stand on vessel to manoeuvre to avoid collision.

They discuss the various factors that determine the ranges that these stages could be considered to be in effect - this includes the speed of the vessels, traffic, other conditions. IIRC, for two large vessels they mark stage 2 as beginning at 6-8 nm, and stage 3 at 2-3 miles. If you consider in the interaction between a freighter and sailboat, that the sailboat is usually quite a bit slower, I would propose that you might move those ranges into about 5-7 nm and 1-2 nm respectively.