The Daria Episode Guide:
Just Add Water

Her amputee boyfriend was cheating, so she stole his prosthesis, but he kept on hopping into strange beds. The One-Legged Lothario, next on Sick, Sad World.

Meet the cannibal with heart; quick, before he eats it! Next, on Sick, Sad World.

Jodie's out selling tickets for Casino Night on a luxury liner, and tries to get Daria and Jane to buy tickets. Unfortunately for Jodie, they've already got plans to watch a Sick, Sad World marathon. The entire Fashion Club is going, of course, and Quinn and Sandi get in a fight about who has the more popular date.
Mr. DeMartino tries desperately to get out of it, but Ms. Li needs to sell all the tickets and have all the adult "volunteers" there so she can buy the "Secure-Fence Shock-Hundred." She also makes attendance mandatory.
Quinn meets a talcum-powder model at the beauty salon, and he actually asks her out, so she switches dates.
Jake is all excited about a new account (involving floating, glow-in-the-dark keychains), but Helen doesn't pay attention to him, so they get into a fight. Jake sulks until he finds out about Casino Night, as the Princess Fairy is looking for a new ad campaign and he thinks volunteering will get him an in.
Daria and Jane stay up late (very late) watching Sick, Sad World, and this holds up the rest of the Morgendorffers when they try to leave for Casino Night the next day, and Quinn gets stood up by Marcos.
Daria and Jane just want to sleep, so they gamble all their chips on a single spin of the roulette wheel. Mr. DeMartino surprises Daria by trying to give her all his chips, as he's got a gambling problem. Instead, Mr. DeMartino ends up in a poker game and cleans out Mr. O'Neill.
Quinn and Sandi have a little non-fight fight, and Sandi starts spreading the word that Quinn's been stood up.
Jake meets the owners of the ship, and DeeDee is immediately enchanted by him (although she's far less enchanted with her husband). Helen doesn't like DeeDee, and when Mr. O'Neill mentions poker she runs off to join the game. DeeDee's husband had to leave to help the pilot, so she and Jake are left alone, and she comes on to him.
Daria and Jane go out on deck to try and get some sleep, but get interrupted by Kevin and Brittany, who then go off to make out in the lifeboat, which breaks free and leaves them floating in the ocean.
Helen and Ms. Li have an intense poker match, with Mr. DeMartino falling by the wayside. Daria actually helps her sister out when the Fashion Club asks her if Quinn was really stood up or not.
DeeDee next approaches Mr. O'Neill, but gets pushed overboard by Ms. Barch.
Jake goes off to drink with and complain to the Captain of the ship, but the guy gets really drunk, leaves Jake in charge, and goes to bed. Jake runs off to get help, but ends up in a fight with Helen about her poker game, and the ship ends up running into a garbage scow. Unfortunately, the ship only ever had one lifeboat, and now it's missing. Luckily, the water is really shallow there, just like most of the people in it. Sandi gets stood up by her, and Quinn's happy again.

"Gee, Quinn, I hope this inability of yours to retain simple information is just temporary and not symptomatic of a more serious, underlying problem." -- Sandi ("Just Add Water")

"Please, Mr. DeMartino! I haven't heard anyone try so hard to squirm out of a school event since Helen Morgendorffer made up that ridiculous excuse about being allergic to crepe paper." -- Ms. Li ("Just Add Water")

"Well, you can just forget it, missy! Jake Morgendorffer doesn't repeat himself! Doesn't repeat himself!" -- Jake ("Just Add Water")

Jane: But first, let's gamble all our chips away in one grand, magnificently pointless gesture.
Daria: That's the only kind of gesture I make.

Mr. DeMartino: Daria, take my chips.
Daria: Excuse me?
Mr. DeMartino: You know, as a thank you for making me want to kill myself a little less than the processed sausages who call themselves your classmates.

"Give the chips away... Poker face... Aah! Poker!" -- Mr. DeMartino ("Just Add Water")

Jane: Back to the serenity of dreamland.
Daria: Yeah. I hope the fire-breathing cyclops hasn't caught me yet.

Jane: We're never going to get any sleep, are we?
Daria: Not unless we kill every living thing on board.
Jane: I'm okay with that.

Wraith's Ramblings:
Not really any character development, but a funny episode with a nice look at the teachers and a revisit of the Helen and Angela Li conflict, as well as a continuation of the Fashion War.
Also see my Rambling of 11-4-00.

Sick, Sad World (the site) was created by Wraith