I am certified, but don't dive in the Pacific NW where you have to dress up in 2" of neoprene to avoid the cold. I prefer diving in a T-shirt, or a 1/6" shorty wet-suit.
If you can afford it, I would suggest considering getting your way I did it:
Trip to Kona - find one of the smaller dive shops (I can recommend one), and get them to do the certification over a week.
I would go out on two trips per day along with a normal dive. The instructor would wait for them to leave, then we would spend time, one on one, in the water covering the basic stuff. Depending on how I was doing, there would usually be a bit of air left after we had finished whatever education/practice the instructor wanted to cover that day, and he would accompany me for the remaining few minutes exploring the area under the boat.
There was no time spent in a pool, it was all in the sea, and even during those first few training sessions, I got to spend some time just diving.
Note that this can only work with an instructor who has the time/willingness to do one-on-one training -- there is no way you could move a class out of the swiming pool and into the sea where you have several students to each instructor.
I had my certification in a week (well, actually 2, because the instructor suggested that since I had the time, it would be good to have some time off, because 2 dives per day when you are learing can get a bit intense).