I found the pretext a little flimsy as well, but found a fine work around from my players no less.
On their first visit to Rickety Squibs, a couple decided to roam the surrounding jungle a bit while waiting for repairs. I had them happen upon a busted up shrine to Gozra conspicuously missing a set of wind chimes, which they took to be the reason for the dry spell. Rickety explained that the last captain there may have been responsible.
They then proceeded to make killing this guy their main mission, and after finally catching him and returnin the chimes, Rickety passed along Tidewater Rock as a suggestion for their expanding enterprise.
