H01

The Subalert vacuum leak detection system installed on a Nikonos V Camera body. Note: the Subalert system consists of the round valve and the plate it is on; the aluminum lever with the orange circle on it is a custom-made strobe cutoff switch and has nothing to do with the Subalert except that they were made by the same person, John Fiorda, of Pacific Camera.

The Subalert Vacuum leak detection system is a unique system that finds leaks in your camera system before you dive. You install a vacuum prior to diving, and the electronics allow you to monitor the vacuum before you dive. The system will detect leaks too small to be harmful. As the vast majority of floods are caused by conditions present before the dive -- bits of dust or lint on the o-rings, pinched, dirty, cracked, or otherwise compromised o-rings, etc. -- this system virtually eliminates flooding!

The Subalert consists of electronics to monitor the vacuum one pumps into a camera or housing prior to diving. If the vacuum fails due to air (or water) leakage, a blinking LED warns of a potential problem. On some models, a vacuum gauge monitors the precise amount of vacuum. It is recommended to put the vacuum in at least 15 minutes before diving to give a slow leak a chance to show. If air can't get in, the much thicker water we dive in can't get in either. The Nik V version goes on the side where the film door latch is, and adds about 1/4" to that side, with maybe another 1/2" for the valve. I found it necessary to modify my Ikelite Rotating Trays somewhat to accommodate this, but the modification was not difficult.

The Nik V Subalert is less than $200.00 US installed. The H model is for housings, and is an aluminum box with an LCD display of vacuum pressure in inches of mercury in addition to the warning LED. It is extremely securely mounted to the housing and travels well. It is about $650.00 US installed, depending on the amount of work required to mount it. For all Subalert systems, a pump is required. A $65.00 US hand pump can handle a Nik V, but an air powered pump is needed for housings (no moving parts other than the pressure gauge). It costs $165.00.

I have not had one single flood while using the system. The partial vacuum eliminates any wiggle or rocking of longer lenses or ports, and firmly seats all the seals tightly for rinse tank and shallow water use. Another major advantage is the complete elimination of any internal condensation when diving in water that is cooler than the topside environment one changes film in.

The URL for Pacific Camera's website is http://www.subalert.com/.

Wide-angle camera rig with Subalert installed.