Kirby Morgan M-48 or Draeger Nova with Comms

[jagould2000]

Anyone have experience diving the Kirby Morgan M-48 or Draegar Nova FFM that have a mouthpiece in them and using them with comms? They sell the 4 pin radio mics for the models that have a bite-down mouthpiece, just not sure how you talk with one in your mouth? Is close to audible?

Thanks

 

[-JD-]

Anyone have experience diving the Kirby Morgan M-48 or Draegar Nova FFM that have a mouthpiece in them and using them with comms? They sell the 4 pin radio mics for the models that have a bite-down mouthpiece, just not sure how you talk with one in your mouth? Is close to audible?

Thanks

View attachment 724229

Disclaimer, I have a KM-M48 but only played around with it a bit and no comms ...

• FWIW ^ That is upside down. The extended mouthpiece sits at the top of the pictured "pod" and the purge valve (partially obscured star-thing) goes at the bottom. Like this:
  
• When you seal the pod to the face (mask) frame, you can use the purge valve to dewater the lower oral cavity of the mask where the mic port is located
• That then gives you the option to talk around the mouthpiece in the oral cavity to use the mic.

The M48 is a hybrid FFM where the eye/nose cavity is "sealed" and completely separate from the oral cavity. From what I remember of the Draeger Nova, it is a more traditional FFM where the air is channeled from the reg, through the eye cavity and then down through one-way valves for inhalation. I don't believe there is any mouthpiece.


The advantages of the M48 hybrid style:

• There is a mouthpiece that you can use to maintain a water-excluded air-path in a flood
• You can exchange pods (and therefore regulators) to swap gasses or move to a backup
• You can use a reg without a pod in place, for emergencies, deco, etc.

Disadvantages:

• No nose breathing
• No defogging

 

[Akimbo]

I have used a lot of FFMs that were made for commercial and recreational diving over more than 50 years. The first criteria has to be a good fit. Most are more forgiving than low volume half masks, but a really good fit is not that common.

Another thing to look at is the spider (head harness), especially when you add 3rd party earphones. It can be a real PITA to stuff the earphones under your hood while while donning the mask.

A third consideration is does the FFM have a surface breathing valve available? You can blow a lot of gas suiting up and swimming to a downline unless you have one. Unfortunately, there aren't many places where you can rent a FFM to try first.

Fourth, is think about barf management. This was part of FFM training in the Navy and commercial diving schools before lightweight hats took over the industry. I understand that very few recreational FFM courses addresses the problem. Granted, divers barfing in the water is relatively rare, but can be deadly in a FFM if you don't know how to handle it. This is especially critical if you plan on using it with pure Oxygen for decompression.

 

[jagould2000]

Thanks everyone - yes I knew the pic was upside down - only one I could find on Google image search that showed the inside / mouthpiece.

I currently own OTS Guardian with their comms system, so very familiar with FFM diving and talking underwater. Was just interested in how comms would work with the added mouthpiece to contend with on the M-48