
All the recommendations and conventional "river wisdom" called for 300' of rope... but that turned out WAY too much for our needs.
The boat has a heavy anchor, and we never used more than 130 feet - even when anchored in 65 feet of heavy current.

Now, we should be good to go - plenty of extra rope but not a huge wad of extra to sink, unravel, or tangle in the bouy.
Time to put it to use!