Both are excellent shops with their own high points. And they also dive different sites so sometimes there`s no need to choose between them if you want to see a particular site on their list. I had the oppurtunity to dive with both during my mid tour leave from Iraq in late May through early June. I enjoyed both crews when I dived with them and in the course of about 11 days, I got in 27 dives.
Ocean Concepts is a highly professional organization and they treat you as a valued customer. They are very careful to dot every i and cross every t when it comes to issues like safety. The initial brief on the boat feels very much like the flight attendants brief before the plane leaves the gate at the airport. I had a definate feeling that I was dealing with professionals anytime I was diving with them. They were always friendly but not overly familiar. They knew the sites they were taking us to backwards and forwards and they made sure to watch out for their customers without being overbearing on the subject. The standard with them was a two tank dive one deep and one shallow in the morning. I believe the normal cost was $100 but I got a military discount at $70 per trip and didn`t make a point of remembering the regular cost. I dived the following sites with them from their boat in Wainai:
The Mahi, Black Rock, Mahaka Caverns, Land of Oz
I was left with the impression that if I were taking a major dive course with them that the training would be very thorough. The problem I had with them was that they were very inflexible with their scheduling. I wanted to take specialty courses to expand my knowledge base and skills not a major course. But if the courses I wanted to take weren`t the ones they had already schedules, I would basically have to pay double was how it was explained to me. I don`t mean that as a slam against them, what they did offer was at a level of profesionalism that impressed the hell out of me and I wouldn`t hesitate to dive with them or take a course from them if their schedule coincided with mine. But, how often does a vacation do that?
I spent more time with Dive Oahu because they better suited my needs. They had plenty of instructors on the boat and they were happy to teach specialties without piling on the fees. They also have a great 5 day package that cost me $385 (I don`t remember if that was a military discount). For that fee, I could dive just about anytime the boat went out. The only limit was that on the afternoon run, their dive classes had priority. But, there was only one day that might`ve been an issue and after 3 deep dives that morning (not the normal schudule, which is usually 1 deep, 1 shallow) I was to beat to see if they could squeeze me in on the afternoon trip anyway. They also had a standard 2 tank dive plan but I can`t remember the cost. I dived the following sites with them from their boat out of fishermans reef, Waikiki:
Sea Tiger, Turtle Canyon, K Pipe and a small reef near it, YO 257
Dive Oahu treats you more like family than Ocean Concepts. They have a much more laid back attitude. Don`t take that easy going feel for slack on safety though. I guaruntee you that Bill knows everything that happens on his boat. They don`t call roll after the dive like Ocean Concepts does which initially made me nervous. But, when I looked closer, I realized that they had 1 dive guide for every 5 or so divers and Bill, the boat captain polled them before he moved the boat and he would often count as well. And, the dive guides always made contact with each of their charges before they gave Bill an up. This shop uses a large panel truck to bring their equipment on the short trip from the shop to the boat and they`ve basically outfitted it as a miniture dive shop. If you show up at the boat missing equipment, they can probably fit you out from that truck. They`ll also bend over backwards to help you out if you screw up. The first time I let lost my grip on my positively bouyant camera, they actually managed to track it down after it had had at least 30 minutes to drift. Yes I said first time. To cut to the end of the story, my sister said to her husband "Honey, I`m getting a new camera. Hawaii has a lot of currents, tie your camera to you and weighting it so its negatively bouyant would be a good idea.
If this sounds to you like I`m advocating Dive Oahu over Ocean Concepts, I`m not. I had to get comfortable with Dive Oahu by paying attention to their safety measures and they can take a little getting used to, but I genuinly enjoyed their company and service. I also very much appreciated Ocean Concepts rock solid professionalism and friendly staff. You just have to weigh the two shops and see which one meets your needs. If I lived on Oahu and wanted to take a specialty course on the fly, I`d be at Dive Oahu in a heartbeat. If I decided it was time to get my Divemaster Card, I`d be scheduling it with Ocean Concepts. And if I was just looking to dive one day, it would depend on who was going to the site I wanted to dive.