Regardless of the navagable route, I have read the story and interpreted that Trevor knows in no uncertain terms that his father is not happy that he's gay, and wishes that he'd stop forcing the issue by suggesting he date girls. I also think Dirk is a closet case, however, and that the attorney is an old lover who was going to help Dirk in the divorce, which went sour when the wife went missing.
I think, also, there was a clue in one of the early chapters when CJ mentioned a freighter with the navigation alarms being unmanned while running on autopilot. Why would that have been put in there as a tidbit if it didn't affect anything else in the story?
MikeL: A new company which bought the old sternwheelers Delta Queen, Mississippi Queen, and American Queen (built 1994), when Delta Queen Steamboat Company went bankrupt in 2002 or 2003, is now in ownership of a sternwheeler, the American Queen, which--when built--was so tall that not only do the smokestacks tilt, but the pilothouse was built on lowering hydraulics to clear the bridges. Nevertheless, during the high melt off and rainy season floods of 1998 or '99, the boat got stuck at its dock in Cleveland between two bridges, which were not drawbridges or rotating bridges, for about 5 weeks until the floodwaters went down enough to allow bridge clearance.