The Future of Diving

Text by Duncan Pattenden

OCEAN REEF NEPTUNE III AND COMMUNICATIONS IN ACTION

In our previous two articles, we looked at the roots of Ocean Reef, the journey of becoming a Full-Face Mask Instructor, and the features of the Neptune III Full-Face Mask. Now, let’s take a look at putting the Neptune III IDM (integrated dive mask) into action.

When doing any dive course, the theory training can feel like quite a chore when you’re eager to jump into the water, but don’t skip this step. Ocean Reef provides ample online lessons and training to help you get the most out of your Full-Face Mask Course experience. The online theory covers dos, don’ts, and simple tips and tricks. Once completed, you’ll be ready to hit the water.

The practical introduction starts in the pool, where the confined conditions allow you to practise skills with ease and adjust the IDM for a perfect fit. Before jumping in, we set the 3-D Equalisation block. Its design allows the equalising system to be adjusted in three directions, ensuring comfortable and effortless equalisation. We also learnt that by removing the ‘communications port’ and shining a light through it, your buddy or instructor can easily spot where further adjustments are needed.

Fitting the IDM is straightforward, but it’s important to follow the correct straptightening sequence. Loosen all six straps, place the mask on your face, and position the strap at the back of your head. Begin by tightening the two middle straps, then the two lower straps, and finally the top two straps. If you get this order wrong, the excess length of the top straps will stick upright like bunny ears once you’re in the water.

There are about 14 in-water skills a full-face mask (FFM) candidate needs to be comfortable with, in addition to the standard SCUBA skills. These include breathing in different positions: on your back, on your side, and inverted. In these positions, one might expect the mask to partially flood, similar to a normal regulator, and to be difficult to breathe from while inverted or on your back. To everyone’s surprise, this does not happen—the mask breathes beautifully in all orientations, giving candidates much more confidence.

Under normal circumstances, the Neptune III FFM cannot flood. To demonstrate this, one of the skills involves attempting to flood the mask. Shoving your index finger through the face seal should do the trick, right? While a normal dive mask would flood, the Neptune III being an ambient-pressure mask, is always balanced with the external water pressure, so there is no pressure trying to push water into the mask, and therefore the mask doesn’t flood.

The next step is to deliberately flood the Neptune III IDM. This is where your Instructor steps in to demonstrate the proper technique. Once you’ve managed to flood the Neptune III IDM, you simply clear it by breathing out or lightly pressing the purge button.

The confined water skills will eventually lead you to the Full-Face Mask ‘bailout’. While you may never need to remove the FFM underwater, this exercise ensures you are confident and prepared when using the Neptune III IDM. This is where you switch from the FFM to standard SCUBA. Divers with Open Water training will recall practising a standard mask and regulator bailout. This is similar, except that refitting (‘donning’) the Neptune III IDM requires a few extra steps, which your Instructor will demonstrate. Your Ocean Reef Instructor is equipped with the latest information and techniques regarding open-water FFM training, ensuring your transition from SCUBA to IDM diving is enjoyable and safe.

There are also skills for underwater communication. We used the Ocean Reef GSM Mercury Through-Water (wireless) comms system, which is a ‘push-to-talk’ system that sends a signal (a beep) to all divers as you activate your mic. This signal helps divers time their breathing so exhaled bubbles don’t drown out speech. It takes practice, but mastering this skill makes a huge difference in communication.

One of the exercises was the ‘dialogue skill’ using an MRT (Modified Rhyme Test) slate. Each diver received a slate with rhyming words (e.g., Coil, Oil, Soil, Toil, Boil, Foil). One diver would say a word over comms, and the others circled what they thought they heard. Being South African, with our diverse languages and accents, this exercise quickly highlighted how accents can affect communication. Repeating this skill reduced misunderstandings and improved accuracy.

In our last edition, we asked if there were any questions. Jill from Mauritius asked how the voice signal reaches your ears when using the Ocean Reef GSM Mercury Through-Water communication system.

This is an excellent question because transmitting signals underwater is more complex than it sounds. Here’s a simplified explanation:

We all use EM (electromagnetic) waves for things like mobile phones, radio, and Wi‐Fi to send data. We can send signals across the world and even to other planets without too much difficulty. However, water poses a bit of a problem because the more conductive the medium is, the better it absorbs EM waves! This ‘attenuation’ in water means that EM waves get absorbed almost immediately and cannot travel any useful distance at all. Instead, we use longitudinal waves, or sound waves. Unlike EM waves, sound actually travels about four times faster underwater than in air and isn’t absorbed as quickly. For communications, we use ultrasound—sound at a frequency higher than humans can hear. Ultrasound carries enough data (bit rate) to allow for clear voice transmission.

The key to using ultrasound is a very clever device called a transceiver. It is made from a piezoelectric material that reacts to pressure and electricity, converting one to the other. Squeeze it, and it makes a current. Shock it, and it expands and contracts. The magic is that you can ‘tune’ the transceiver to both send and receive an ultrasound wave, and in turn, convert the ultrasound to an electrical signal that can be used with standard electronics.

So now that we know how each part works, we can understand how we are able to talk to each other underwater.

When you speak into the microphone, it converts your voice sound waves into an electrical signal that is sent to the Ocean Reef GSM Mercury unit, which converts the signal into a format that the transceiver can use.

The transceiver vibrates, creating ultrasound waves that travel through the water.

The transceiver on your dive buddy’s Ocean Reef GSM Mercury unit resonates with the ultrasound waves and sends an electrical signal that is once again converted and sent to their earphones, which then vibrate the water with normal sound waves that reach your ears through the water. You can also adjust the volume of the earphones to compensate for your dive hoodie and hearing requirements as needed.

In total, your voice is transformed four times —back and forth between sound waves and electrical signals—to overcome the challenges of underwater communication.

The Ocean Reef Neptune III IDM and Communication System represent the future of recreational and professional diving. By combining cutting-edge equipment with structured training, divers can improve safety, streamline skills, and enhance their overall underwater experience. In our next article we’ll cover how the Neptune III IDM and Comm Systems can be used for both recreational and commercial diving, stay tuned!