Well I was an idiot and hydrolocked my Prelude about 3 years ago. So here's a few tips.
Change the oil as soon as you pump the water out, mine looked like chocolate milk. Engine damage may not be easliy identified after you get it restarted. I felt a very slight pulse at idle and had two dealerships and an independent shop give it a clean bill of health. I checked the compression myself and found the #4 cylinder low. Within Hondas specs but not within mine. Took it back to the independent and they mesured the stroke. #4 was quite a bit shorter! No knocking or anything, but upon removal the rod was badly bent. As the engine aged knocking and other damage would become an issue. Compression and leakdown tests are your friends. Insurance did cover the damage.

 

I was driving thru a puddle when it sucked water in. However I was going very slow when it happend. I was about 18" away from clearing the puddle when one of the waves that my car made was sucked into my AEM and the car just stopped!

the engine was so locked that I tried to pull the car in gear (with my truck) to see if it would break the engine loose and all that the car would do is drag the wheels.

So seeing it was newyears eve and I was 2 hours away from my birthday, we got the car home and went drinking, worried about the car the next day (good times)