Disaster movies have been fine-tuned by Hollywood into a fairly reliable and polished formula. One of the ingredient is usually a good dose of melodrama. Now, Asian cinema as well, is known to spice movies with melodramatic bits.
It therefore doesn't take a rocket scientist to figure out what an Asian take on disaster movies is gonna end up looking like: A melodramatic extravaganza.
The first hour of Haeundae (also known as Tidal Wave in English) consists of setting up the table by presenting the cookie-cutter characters (played by a rather weak cast which tends to overact) and their clichés relationships. The script and story is pretty standard for the genre (you've seen all of this in Twister, Armageddon, many of Emmerich's movies and so on) but the writing is just... immature. As if the script came straight from a high school play. I must still praise some of the comedy bits, which are indeed funny and make certain characters more likable. Unfortunately, the dramatic bits are as (unintentionally) funny as the comedic ones and that is a problem.
The final part of the film is where the disaster unleashes and ends up being a poor payoff. The special effects, cinematography, editing are uninspired. This film suffers from poor direction and you immediately feel like you'd rather catch an old disaster flick on cable TV. But what absolutely kills the disaster scenes are the tear-jerking attempts. It's like the director is trying to squeeze a dehydrated fruit and fill a glass with orange juice.
It still deserves a 3 because there is some heart to it and it maintains your interest with some of the quirky characters. Plus a few comedic bits are also worth it. But if you're not a fan of the genre, expect a big waste of time.