With the release of Spelljammer for D&D 5th Edition, I decided to break out the second AD&D Spelljammer module Skulls & Crossbows. I'm looking at it particularly with quick conversion in mind, but also for story and general usefulness. The sixth adventure in the book is called "Fire and ice."
The player characters have heard reports that shipping in some sector of Wildspace has been suffering lately. Rumour has it that piracy is to blame and incidentally the ship that gets named is one of the ships on the player character's bounty hunter list. Presumably, the players hurry to the troubled region of Wildspace. when they arrive, they witness a ship of the Astral Elves' navy being bombarded by a squid-ship.
It turns out that the squid-ship has been taken over by a trio of giants (two fire giants and one frost giant), and they've been plundering whatever they please. What's that mean? That's right, it's another ship battle.
Giants aboard a squid-ship is ultimately neither here nor there. It doesn't lead to a bigger story (or if it does, that's not revealed here.)
I gather that the actual purpose of this encounter is to establish the true alignment of the player characters. There's an elven naval vessel in need of assistance, and the PC reputation with the elven navy depends on their actions.
Squid-ship stats are provided in Astral Adventurer's Guide, and obviously giants are giants from the Monster Manual.
The elves are in a man-o-war, which is secretly included in 5e as the Star Moth (page 50 of Astral Adventurer's Guide.)
The next section of the book is for levels 7-10, starting with an adventure named "Violent Death." That bodes well!