motogpfan
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a buddy of mine has one of these and said without dive gear he can pull up a skier, now I'm not talking slalom skier, just 2 skis but still that's pretty impressive.
BLADEFISH Sea Jets - A Completely Different Approach
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200 feet per minute? If this is the case - the Bladefish is way faster than a Gavin, or Dive Extra with a Lion battery. The comparative data being from the Tahoe Benchmark 98.'
* Gavin short - 166 fpm
* Submerge N19 - 202 fpm
* DSS Lion - 195 fpm
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commanderscuba
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xxxxx
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commanderscuba
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To be fair, on the box of the Bladefish 5000 there is an asterik next to the speed claim of 3.3 mph. I'm looking at it right now. Based on my use and experience with it, I would not be surprised if it pulled a 60 pound person that fast - at least briefly.
You'll notice your statement is false as evidenced by
http://www.scubaboard.com/forums/5390097-post225.html. But nice try anyway.
Bottom line is these DPV's mark a great advancement for recreational divers who are looking to extend their range and bottom-time in an affordable and convenient way. Personally, I will be investing in a more expensive and powerful scooter at some point in time, but it won't be because of any fault of the Bladefish. And the Bladefish will still be my go to for air travel and dive boats.
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DeusVerto
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As an electrical engineer with 6 years of (part time) high-current battery and motor control design experience, I thought I would weight in with my opinion. I have not ever seen one of these, so this is just that - my opinion.
While the speed claim is certainly a subject of some debate, it wouldn't be the first time the marketing department of a company lifted it's proverbial middle finger at the engineering staff while writing the advertising copy. While I too am rather put off by this, I encourage everyone to judge the product on it's own merits for their particular use case. Perhaps the company's engineers knew what they were doing and salespeople...will be salespeople.
Knowing almost nothing about the product, yet armed with the knowledge of 200 watts, 18 Volts, 45 minute run time, and lithium ion technology, I have my own questions.
Assuming 75% power as a "cruise" setting, this means the battery would have to deliver 8.3 amps for 45 minutes, or be about a 5-cell 11Ah unit. Even with the most consumer-unfriendly* lithium polymer packaging, that's about a 3 pound battery which at direct importer wholesale is about $150 USD, making it undoubtedly the most expensive component in the device, possibly more than the whole rest put together.
*I say "consumer-unfriendly" because lithium polymer batteries have a shelf-life of about 3 years. Meaning, they lose much of their capacity after three years, whether you use them or not, regardless of the number of charging cycles.
Those of you with laptops that are over 3 years old...you know what I mean.
How are they going to handle the inevitable battery replacements? What will they charge? I would ask before buying one. A visit to bladefish.net seems less than encouraging; they make no mention of anything but the superiority of lithium ion. I think if they were employing the new, truly superior lithium phosphate technology cells, they would say so. But I doubt (at half the energy density of lithium polymer and twice the cost) they are doing so.
You you wish to read more, search for A123 Systems website, which includes quite a bit of comparative battery technology data.
What do you want to bet this thing is made in China? Hmmm?
I might just get one myself to play with, knowing that I could replace the cells myself in 3 years if I had a mind to. That said, I won't be using one to go farther from the boat (or shore) than I could safely swim under my own power.
While the speed claim is certainly a subject of some debate, it wouldn't be the first time the marketing department of a company lifted it's proverbial middle finger at the engineering staff while writing the advertising copy. While I too am rather put off by this, I encourage everyone to judge the product on it's own merits for their particular use case. Perhaps the company's engineers knew what they were doing and salespeople...will be salespeople.
Knowing almost nothing about the product, yet armed with the knowledge of 200 watts, 18 Volts, 45 minute run time, and lithium ion technology, I have my own questions.
Assuming 75% power as a "cruise" setting, this means the battery would have to deliver 8.3 amps for 45 minutes, or be about a 5-cell 11Ah unit. Even with the most consumer-unfriendly* lithium polymer packaging, that's about a 3 pound battery which at direct importer wholesale is about $150 USD, making it undoubtedly the most expensive component in the device, possibly more than the whole rest put together.
*I say "consumer-unfriendly" because lithium polymer batteries have a shelf-life of about 3 years. Meaning, they lose much of their capacity after three years, whether you use them or not, regardless of the number of charging cycles.
Those of you with laptops that are over 3 years old...you know what I mean.
How are they going to handle the inevitable battery replacements? What will they charge? I would ask before buying one. A visit to bladefish.net seems less than encouraging; they make no mention of anything but the superiority of lithium ion. I think if they were employing the new, truly superior lithium phosphate technology cells, they would say so. But I doubt (at half the energy density of lithium polymer and twice the cost) they are doing so.
You you wish to read more, search for A123 Systems website, which includes quite a bit of comparative battery technology data.
What do you want to bet this thing is made in China? Hmmm?
I might just get one myself to play with, knowing that I could replace the cells myself in 3 years if I had a mind to. That said, I won't be using one to go farther from the boat (or shore) than I could safely swim under my own power.
bigblue_hi
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I think a better question is whether they will still be in business 3 years from now..
As for all these people saying "Hey leave us alone.. let us have our ignorant bliss" - there has been discussion of paraplegic/older/unfit divers using these. I sure as heck wouldn't trust my life on some overhyped junk that makes wild claims.
Obviously there is a market for recreational scooters with lower reliability/engineering levels than tech-rated scooters. Certainly not everyone needs one that goes to 600 feet and it makes sense to engineer one to rec limits as the market is much, much larger. Personally I'd love something that zipped me along at 1.5mph but I have no illusions about picking one up at the bargain bin at Kmart.
Personally I'd probably just build one myself or get a used tech scooter.
P.S. rapidiver do you work for them or something? You're quite diligent in supporting them but I haven't seen you perform any sort of basic speed run. Not difficult at all. Mark a straight course with a line (say.. 100m). Do a few runs. Average the results of an even number of opposite runs (to correct for current). This would give a reasonable ballpark, and if you're 205lbs this would not vary wildly from most other divers on here.
I get that you feel like you "really move along" when using one, but that's hardly objective. It feels like I'm going faster when I have the windows down in my car - ahh that wind noise! I'm actually losing efficiency though, being less aerodynamic due to the additional drag. Same reason why convertibles are so fun.
As for all these people saying "Hey leave us alone.. let us have our ignorant bliss" - there has been discussion of paraplegic/older/unfit divers using these. I sure as heck wouldn't trust my life on some overhyped junk that makes wild claims.
Obviously there is a market for recreational scooters with lower reliability/engineering levels than tech-rated scooters. Certainly not everyone needs one that goes to 600 feet and it makes sense to engineer one to rec limits as the market is much, much larger. Personally I'd love something that zipped me along at 1.5mph but I have no illusions about picking one up at the bargain bin at Kmart.
Personally I'd probably just build one myself or get a used tech scooter.
P.S. rapidiver do you work for them or something? You're quite diligent in supporting them but I haven't seen you perform any sort of basic speed run. Not difficult at all. Mark a straight course with a line (say.. 100m). Do a few runs. Average the results of an even number of opposite runs (to correct for current). This would give a reasonable ballpark, and if you're 205lbs this would not vary wildly from most other divers on here.
I get that you feel like you "really move along" when using one, but that's hardly objective. It feels like I'm going faster when I have the windows down in my car - ahh that wind noise! I'm actually losing efficiency though, being less aerodynamic due to the additional drag. Same reason why convertibles are so fun.
commanderscuba
Registered
You guys are the biggest haters ever. The Bladefish 5000 rocks. I just took it out on Spiny Lobster Season opener in San Diego, October 2, 2010. We scootered out to the first set of lobster traps which are not yet baited and cleaned shop. The BladeFish took us right to the dive spot and back with battery to spare. In fact according to the battery indicators, we didn't even use half. I made it back to shore with less than half of the battery exhausted. Check....extended range-300 yards.
Needlesstosay, lobster opener was good!
Needlesstosay, lobster opener was good!
DeusVerto
Contributor
Haters? I don't hate anyone. I'm just an engineer and the guys who make the Bladefish live in the same time/space continuum I do. Perhaps their unique compromises to achieve this price/performance point are worth a look, and their marketing guys ham it up because that's what marketers do. I am saying that buying one with both eyes open is better than not.
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