Welcome to Okinawa Institute of Science and Underwater Technology "No Limit"


Okinawa Institute of Science and Underwater Technology "No limit" is the leading Rebreather training facility in Okinawa Japan.

We are the Closed Circuit Rebreather Specialists, offer the full range of IANTD and IART Rebreather training programs from Sport Rebreather diver up to Rebreather Instructor levels.

We provide scientific diving services through inspections, sampling,  surveys, contract oversight, and long-term monitoring as well.

We are an authorized dealer and an Instructor as rEvo, Hollis, AP diving, Innner Space Systems, KISS and Shearwater Reseach dive computer.  


Rebreathers allow us to dive deeper depths and longer penetrations with less gas on our back.  If you are interested in doing any courses with us. Please contact us for more information.


※Rebreathers are not all the same.

Our recommendation to divers seeking rebreather training is to select an instructor having several hundred hours of rebreather dives and who dives rebreathers exclusively. No rebreather is foolproof, and the fact remains that compared to open circuit there seems to be a disproportionate number of rebreather fatalities, nearly all of which have been attributed to diver error. Your safety while diving is controlled by you, not by your rebreather.


"For the diligent diver, closed circuit rebreathers are actually safer than open circuit scuba." by Tom Mount IANTD CEO


How much teaching experience on this unit does your potential instructor have?

You might want to enquire and get proof of how many CCR classes your potential instructor teaches each year.  Do you really want to be trained by someone that teaches this kind of diving occasionally? It costs just as much for a full time, experienced CCR instructor as it does for an inexperienced one…think about it. You might also be skeptical of discounted training prices. More often than not, you will get what you pay for. Less never equals more in the rebreather business.


FAQ: Rebreather Myths