Delfjet scooter

[TJO]

Anyone seen and tried this one?

http://www.delfjet.com/

[Genesis]

are the speeds they're citing real?!

How expensive is this beast? :)

[TJO]

Genesis, those are my questions as well. Is this really possible? 20 km/h uw? I wonder if it is possible to keep the regulator in my mouth and the mask on my face... I have no information about the price but sent them an email.

[Genesis]

anything is possible.

Whether you'd WANT it to be possible is another matter.

7 mph is SMOKING; you'd be losing gear at that speed (like your mask!), if its real.

[bmazin]

This looks too polished to be a joke, and their numbers mostly work out. My professional opinion - pretty cool.

They claim 3.5 kW of power (5 hp) and 125 lbs of thrust (570 Newtons) - this works out to 25 lbs/hp, a fairly typical number.

Their speed claims for a scuba diver are dubious. 40 lbs of thrust from a regular scooter gets a scuba diver about 2.5 knots. As a basic estimate, say drag goes as speed^2. So 120 lbs of thrust would make around 5 knots - this is still pretty impressive. A skin diver might see 7 knots (or might not, if their mask gets ripped off).

Their battery life claims are pure fiction. 40 Ah cells discharged at 110 Amps (numbers from their website) gives 20 minutes at full burn - not the 60 minutes they claim.

What is most telling is the lack of a price on the website. The Li-ion batteries are very expensive, and so are their electronics, molds for the body, etc. - my uninformed guess is this will be quite a bit north of $10000 - better to think of it as a high end electric jetski then a scuba scooter. That said, it looks quite well made from the pictures, and should be a blast to use.

Ben Mazin
MST, Inc.
http://www.jetboots.com/