At 05:22 the location is shown as Muertos Trough. "Muertos" is Spanish for "Dead men".
At 45:05 Dr. Westphalen says "Damn the torpedoes and full speed ahead" which paraphrases US Admiral David Farragut's order during the battle of Mobile Bay during the American Civil War. At the time sea mines were referred to as "torpedoes" and Mobile Bay had been heavily minded, making the assault on the bay particularly dangerous to Farragut's ships.
Sandy McPeak appeared in Blue Thunder (1984), the TV adaptation of Roy Scheider's film Blue Thunder (1983).
The treasure hunters are on Monito Island. "Monito" is Spanish for "little monkey".