The town council of Saltmarsh is concerned. They have several clues that seem to indicate that the Suarian who have long kept to themselves to the south west of town are arming themselves heavily. A note seems to indicate they are upset at invaders, and it seems like Saltmarsh might be the target, as the Saurian were on this island long before the little town was built over 70 years ago.
This fan-made conversion of U2: Danger at Dunwater acknowledges the source material and credits but makes fairly extensive alterations to the original. The use of original maps and art probably is copyright-infringing.