Diver to attempt cross-channel (England-France) scuba dive with scooter.

[cool_hardware52]

Love to see this scooter. 160 meters / min = ~6 mph.

The fastest scooters at Tahoe were ~3 mph and required ~ 1500 watts to achieve this.

Power required rises as the cube of the velocity.

6mph /3mph = 2 2 cubed is 8

1500 watts x 8 = 12,000 watts or about 16 horsepower.

The current best Lithium batteries provide about 100 watthour per pound. The battery necessary to run a 12 kw scooter for even one hour would weigh about 120 lbs.

Tobin

 

[BDSC]

I say he doesn't make it.

 

[mala]

If the dive is conducted without any surface support, it would be interesting to track on a purely navigational basis.

the scooter does 9.6kph so that would be a 3 hour dive with a 2 hour deco.

they have allowed 8 hours -so looks like he plans to be lost for 3hrs.

 

[cool_hardware52]

the scooter does 9.6kph so that would be a 3 hour dive with a 2 hour deco.

they have allowed 8 hours -so looks like he plans to be lost for 3hrs.

Sounds like they are planning on ~200-230 ft / min, not 530 ft/ min. That's both possible with todays scooters, and possible for a diver to tolerate.

At Tahoe each test diver ran the scooters for 1 mile at wide top speed, and was replaced by a new test diver. It is physically very tasking to ride a scooter at ~280-300 ft /min, much less so at ~200 ft min.

IMO there is no way a diver could tolerate 6 mph with a tow behind scooter for more than a few seconds.

Tobin

 

[NJDiver_Chris]

I'm sure he will have some surface support in case it all goes wrong, but they will need to watch out for the shipping lane traffic. He will also need to be deep enough to not get slammed by a cargo ship crossing by.

 

[Dive-aholic]

I would think its going to be a shallow dive.

Then why the 2 hour deco?

---------- Post added ----------

At Tahoe each test diver ran the scooters for 1 mile at wide top speed, and was replaced by a new test diver. It is physically very tasking to ride a scooter at ~280-300 ft /min, much less so at ~200 ft min.

I regularly ride my scooter in the 200-250 fpm range. I've never had an issue. It's actually pretty relaxing for me. I'm sure this is the case for others here in Florida as well.

IMO there is no way a diver could tolerate 6 mph with a tow behind scooter for more than a few seconds.

Tobin

This I agree with. 160 meters/min is fast!

 

[cool_hardware52]

Then why the 2 hour deco?

I regularly ride my scooter in the 200-250 fpm range. I've never had an issue. It's actually pretty relaxing for me. I'm sure this is the case for others here in Florida as well.

200 ft / min is easily tolerated. 250? not so much. I own two scooters capable of ~300 ft / min, and speeds above ~220 are an acquired taste.

I'd have to ask, how do you know you are routinely in the 250 ft/min range? Without a measured course and time keeping it's very difficult to estimate speed.

The load on the diver increases with the square of the velocity, Very small increases in speed are often incorrectly perceived by the diver as much greater than they really are.

This I agree with. 160 meters/min is fast!

Way beyond fast, right into fantasy land. The laws of physics haven't been repealed, last I checked.

Tobin

 

[JamesK]

200 ft / min is easily tolerated. 250? not so much. I own two scooters capable of ~300 ft / min, and speeds above ~220 are an acquired taste.

I'd have to ask, how do you know you are routinely in the 250 ft/min range? Without a measured course and time keeping it's very difficult to estimate speed.

The load on the diver increases with the square of the velocity, Very small increases in speed are often incorrectly perceived by the diver as much greater than they really are.





Way beyond fast, right into fantasy land. The laws of physics haven't been repealed, last I checked.

Tobin

I can't speak for Rob, but a lot of our caves have distance markers in them making it a little easier to keep track of your feet per minute.

Me, I am not a great scooter driver. I have not scootered but a few times in the last few years. 200fpm is more then plenty fast for me.

 

[cool_hardware52]

I can't speak for Rob, but a lot of our caves have distance markers in them making it a little easier to keep track of your feet per minute.

Me, I am not a great scooter driver. I have not scootered but a few times in the last few years. 200fpm is more then plenty fast for me.

Again, the difference between 200 f/m and 250 is huge. Even 15 fpm is easily detected by divers and s often assumed to be far far greater a difference.

Tobin

 

[LandonL]

Then why the 2 hour deco?

The article says he plans to do the entire dive without surfacing, and that it will take him around 8 hours.