I'll look it up. I don't happen to own a copy, but have been meaning to buy one.
I looked for an onlne excerpt but can't find your reference.
The problem I see in the recreational boating world, is that many boaters are barely familiar with all the Basic Coast Guard rules, let alone all the nuances, and court rulings. Those that do read the GC rules will find no mention of current travel except as previously mentioned.
On tidal waters, where the current reverses 4 times a day, many power boaters would be hard pressed to tell you which way the current was flowing as they just apply more power.
I will however obtain a copy of Farwell's to see what they have to say.