The plots certainly aren't any less implausible compared to most other procedurals, or compared to the original Five-O,
for that matter. The McGarrett/Danno banter is the best thing about this series, although the episodes have
gotten better. I'd say starting with the one back in November where Danno's former partner on the HPD, that was the turning point.
Of course, it also helps that I've been watching the original series on DVD at the same time (currently on Season 6). It's nice to see how many nods to the original series they've managed to work in so far while still letting it be its own thing; the original Five-O
was a product of its place and time, and the new Five-0
is as well.
I haven't seen tonight's episode yet (didn't know it was on tonight instead of Monday), so I'll have to wait for it to show up OnDemand. I did read the episode description, and the fake tsunami warning was an episode back in Season 2; that time, the warning was a cover so Wo Fat could try and sneak out of the islands with a brilliant geneticist (played by Will Geer, a.k.a. Grandpa Walton).