We transfer the rescuees to Redlarch officials to deal with and catch
some sleep.  In the morning, a large mass of water is seen approaching
the town.  It's not clear exactly how it does this, as it's essentially
flowing uphill (and looks like a stationary tidal wave from afar), but we
eventually decide it's some weird boundary between the elemental plane of
water and the prime material.  As we scope out the town's escape route,
the water priestess gets our attention and tells us they "need to make
it look good" but that we're taking too long.  We take the hint, head
back to town and speed up the evacuation (as well as taking rear guard,
rather than the van).

As the water laps at the base of the dike the smith's devotees had
erected to give them time to finish their ark, three dire trolls emerge
and attack it.  For all their size, they're surprisingly easy to put
down, although they do plenty of damage, and we have help from the giant
we'd brought back to town.  30k/6.5 xp.  Roughly an hour later, the
next wave approaches, and Rimardo uses some water tricks to buy enough
time to complete the group's short rest and ready the ship for launch.
Two water demons and one dragon turtle approach, backed by five water
elementals who essentially cancel out Rimardo's ability to permanently
banish the demons.  We maneuver to protect the ship, setting out in our
own folding boat, and eventually do away with the demons, the turtle
turning back after taking (and giving) a boat-load of damage.  29k/6 xp.