Something that would be unlikely to come up in Dallas is research on how to interpret the whistle signals of the tug that Lyman heard this early morning.

As he heard it, the boat was moving slowly and blowing a succession of one prolonged then two short blasts.

The international rule of navigation reads this way:

Rule 35 Sound Signals in Restricted Visibility

In or near an area of restricted visibility, whether by day or night, the signals prescribed in this Rule shall be used as follows.

(a) A power-driven vessel making way through the water shall sound at intervals of not more than 2 minutes one prolonged blast.
(b) A power-driven vessel underway, but stopped and making no way through the water, shall sound at intervals of not more than 2 minutes two prolonged blasts in succession with an interval of about 2 seconds between them.
(c) A vessel not under command, a vessel restricted in her ability to maneuver, a vessel constrained by her draft, a sailing vessel, a vessel engaged in fishing and a vessel engaged in towing or pushing another vessel shall, instead of the signals prescribed in paragraphs (a) or (b) of this Rule, sound at intervals of not more than 2 minutes three blasts in succession, namely one prolonged followed by two short blasts.

When I woke at seven this morning, the weather channel reported that the whole area was foggy.