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Extreme Dolfinism G2

REVAN

The Right Stuff
Mar 19, 2009
808
351
118
Arizona, USA
www.smithaerospace.us
FYI: I have Pilot2 monofins up for sale at smithaerospace.us. Also, the original Pilot monofins are available with free shoes installed if I have what you want in stock.

Here's the current list of sizes: I have 36, 37, 40, 41, 42, 45 and 48 available.

The difference between the Pilot and Pilot2 is that the Pilot uses a bolt pattern compatible with shoes using the 4 hole SPD nut plate, and the Pilot2 uses a bolt hole pattern compatible with shoes that use the 3 hole "Look" system.
 

REVAN

The Right Stuff
Mar 19, 2009
808
351
118
Arizona, USA
www.smithaerospace.us
I took my latest scuba project out into open water recently. Conditions were terrible, bad visibility and cold (only 60 F on the bottom), but at least there was no current, so that will not interfere with the perceived speeds as captured on video. I had a chest mounted camera to video of the swim. It's not good video, but it is what it is. At least it shows some perspective of the swimming effort and speeds. This is a scuba kit that swims a little more efficiently than when I'm swimming as a freediver. So, in this case adding scuba actually makes me more efficient in the water. I seems backward, but that what good streamlining can do.

I had several system problems this first time out. Before trying for more OW testing, I'll need to go back and change some things. So, I've got some work to do before I proceed toward further development to complete the kit's intended function, as the current partial function isn't really all there. At this point all I can say for sure is that it is really efficient, and that makes it fast. I'm pretty sure I was exceeding 4 knots during some parts of the video, and that's not at maximum effort (note the fairly normal breathing rate).


YouTube Text

Open water testing the Nekton CFM80 streamlined scuba kit with a DOL-Fin Orca2 Monofin for propulsion:

This open circuit scuba kit uses a standard aluminum 80 cubic foot scuba tank. Through aggressive streamlining and a highly efficient monofin for propulsion, this system cruises at speeds exceeding 3 knots. It does this without batteries or motors and with a sustainable level of effort that is equivalent to walking. The Nekton CFM80 is an incomplete prototype and we are not showing any details of the kit at this time, but the swimming performance can clearly be seen to be much, much faster than the typical scuba diver, and compared to DPV systems this is extremely quiet (stealth in both EM and acoustic signatures).

Between the equipment streamlining and improved thrust efficiency of the monofin, this kit is presently estimated to achieve an overall hydrodynamic swimming efficiency of approximately 20 to 25 times greater than a typical recreational scuba diver. This increased efficiency results in speeds that are about 3 times faster than typical scuba diver swimming speeds for a given level of effort. Coupled with a closed-circuit rebreather for endurance, instead of an open circuit scuba tank (as is being used here), a diver could reliably cover a distance of over 12 nautical miles in a 4 hour dive interval.

The Nekton CFM80 is presently just an R&D project. However, the diver is using a DOL-Fin Orca Mk-2 Monofin from Smith Aerospace Corp. The Orca monofin is a fully developed and commercially available product.

More testing to follow as engineering development continues....
 

REVAN

The Right Stuff
Mar 19, 2009
808
351
118
Arizona, USA
www.smithaerospace.us
I've been spending a lot of time working on my airplane project lately, but I've got an opportunity to do a little diving this weekend. I've got the Orca2 monofin packed and will do some more OW testing with the Nekton kit, but I'm really just looking forward to doing some freediving again.

I came across this video from a few years back. It was refreshing to watch it again, so I hope you'll enjoy it also.

 

REVAN

The Right Stuff
Mar 19, 2009
808
351
118
Arizona, USA
www.smithaerospace.us
This is video I shot with my latest scuba kit and swimming with a DOL-Fin Orca2 Monofin. I think I'm getting pretty good quality with this setup; nice and stable video. Plus, it swims very efficiently and super fast when needed. It would be ideal for diving blue water with whales and other large fast animals.

 
Likes: Billfish

REVAN

The Right Stuff
Mar 19, 2009
808
351
118
Arizona, USA
www.smithaerospace.us
This post is in the scuba section of the forum, but I thought I'd make a reference to it here. If you find this interesting and want to follow it, you should be able to jump to the original post by clicking the popup arrow behind the name header at the top of the box.

SCUBA is the Nekton S80 Proof-of-Principle Experimental Prototype. Propulsion is a DOL-Fin Orca Mk2 Monofin from Smith Aerospace Corp.

Stats this dive:
* Total Distance Covered - Greater than 1.6 miles
* Surface Swim Distance - 0.4 miles
* Max Depth - 68 feet
* Average Depth - 40 feet
* Submerged Dive Time - 90 minutes
* Total Air Consumption - 50 cubic feet

I'm cruising the edge of blue water in search of hammerhead sharks coming in for a reef cleaning. Though none were found on this dive, it was still a nice dive and a good example of what this equipment can do.

Note that this dive was about trying to find the sharks, not about maximizing distance for the sake of it. The "Distance Covered" stat, doesn't include the all the little meanderings of the search, only the macro path as could be extrapolated from the area map. I'm estimating that I was actively swimming about half the time and loitering/looking around the other half.

I'm finding that I can get a solid 2 knots cruise speed from this kit, with a SAC rate equivalent to not swimming at all. So, the 50/50 split, between swim vs. loiter, really only affects the distance covered metric, but not the dive time or total air consumption metrics. This means that my SAC using this kit is will also be lower than my SAC rate on a scooter, because here I'm not fighting motor torque (there's no noise either).


PS - Cruising at 3 knots is also easily achieved with this kit by switching to a continuous kick cycle. At 3 knots, my SAC is slightly elevated and about equivalent to that of casual walking. In a sprint, I think that speeds somewhere up around 5 knots are likely, but I don't have any good measurements of this yet.
 
Likes: Chipswim