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Rockbox AMPD vs Velocitek ProStart


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#1 rexdenton

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Posted 06 April 2011 - 07:34 PM

Before I drop 6 bills on another electronic gizmo, maybe some here can help me form an opinion.

Thanks,
Rex

#2 Blackadder

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Posted 06 April 2011 - 10:50 PM

I have both.

The ROCKBOX has an extended range of functions and can be used for line calculations, but its not easy and takes a while to get used to. Prostart is simple to use and basically gives timer, line functions then speed/heading, it also has a primitive head/lift function. You ncan enter waypoints into rockbox.
Rockbox has backlight so is good at night. Prostart does not have backlight so is not good at night.
Rockbox chews batteries and to replace the battery you have to undo 4 fiddly screws and take it apart. Prostart has a snap off cover.

If you don't sail at night i recommend Prostart

We like having both, we don't use any other instruments.

#3 Pewit

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Posted 07 April 2011 - 02:46 PM

Before you splash out, take a look at iRegatta for iPad/iPhone. Does most of what dedicated kit can do for $10!

Uses built-in GPS or will take NEMEA data over wi-fi.

Before I drop 6 bills on another electronic gizmo, maybe some here can help me form an opinion.

Thanks,
Rex



#4 Blackadder

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Posted 09 April 2011 - 02:59 AM

Not sure if I would want to mount my iphone on the mast :-)

Also battery life for anything other than an hour or two would be an issue. iphone apps great for limited use though or as backup.

#5 clamslapper

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Posted 13 April 2011 - 03:00 AM

The iRegatta app for the iPad is totally amazing. If you already have an iPad, by no means should you buy one of these sailing-specific gadgets.

I'm not totally clear on whether the iPad's GPS function -- and thus the start-line function -- is as accurate as on the RockBox or ProStart. But why wouldn't it be? It has worked for me in about a dozen starts. Anyhow, if the accuracy is the same, there's little point in getting one of these units -- an iPad gets 10+ hours of battery life, and as long as you can splashproof it and figure out somewhere to mount it (I mount mine on the back of the companionway spinnaker launch bag), you're golden.

I especially love the iRegatta function of "Time to Line" -- the ProStart has no such thing, and I don't think the RB does either. That's a pretty serious piece of America's Cup-style functionality.

#6 smokeless

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Posted 13 April 2011 - 09:34 AM

The iRegatta app for the iPad is totally amazing. If you already have an iPad, by no means should you buy one of these sailing-specific gadgets.

I'm not totally clear on whether the iPad's GPS function -- and thus the start-line function -- is as accurate as on the RockBox or ProStart. But why wouldn't it be?


From the developer's own iTunes description (SIC):

Of cause the GPS of the iPhone does not have the same accuracy and update rate as an professional device like fore instance the Velocitek instrument, but if you have an iPhone anyways, this is a cheap way to introduce you to the benefits of a GPS device, to help you leverage your regatta sailing performance.


the iPad uses the Broadcom BCM4750 chip for GPS, and from their own literature:

Broadcom provides a software library that realizes the GPS navigation solution in the host using minimum resources and with no real time requirements.


While better than nothing, I wouldn't rely too heavily on it. I've used the velocitek and Deckman/Expedition start features and I always prefer distance to line over time to judge things unless you've dialed in your polars/acceleration rates for different windspeeds.

My preference is for the Prostart (or Rockbox) on SBs as they are waterproof, durable (-ish) and iPads suck to read in full sunlight; it mounts on the mast and gives the crew a second display that is used throughout the race. I've found iPads to be OK for a daysail as a backup, but less than ideal in a racing environment.

On bigger boats with someone standing at the back a handheld running Expedition is preferred. I've found that iPads that spend time in a racing environment aren't long for this world.

Edit: on my SB which doesn't race at night we have the ProStart and an iPad as a backup chartplotter; no real experience with the AMPD

#7 E-quilibrium

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Posted 15 April 2011 - 02:53 PM

Ok, i am about to buyone of the two, and am the sort who like analysis. I am just going to compare the prostart and the rockbox, since that was the comparison called for in the subject line. Plus i hate apple! Posted Image



I. Information

The purpose of a tactical computer, first and foremost isto inform the skipper and crew on what the hell is going on. The following arethe different types of info each unit gives:



----------- ROCK BOX Pro Start

Heading x x

Speed x x

VMG x -

Dist.To line x x

Timeto line x -

Countdowntimer x x

Headerlift with auto set x x

WaypointBearing x -

Timeto waypoint x -

II.Display of information

You have to be able to receive theinfo the computer generates! The Rockbox has 27 different ways to display it's9 types of data. The Pro start has two ways to display its 5 types of data.Thus, the rock box wins on different display combinations, hands down.

You also have to be able to see whatis being displayed. Rockbox has a bigger screen, and a backlight for use atnight.

III.Special features

I will only comment on the featureswhich each unit has EXCLUSIVELY, meaning if they both have it, I'm not going tomention it.

--------------------------------------------Rockbox-------------------------------------------------------

Autowind direction finder

Displayswitcher (when you head downwind the type of info displayed will change)

Frequencyof logged data points is adjustable (for example: so you can track for 3 hourswith a low interval between data record points, or 60 hours with just a longtime between data points)

MaximumVMG

Backlight

Graphicaldisplay of heading, speed and VMG

Distanceto line feature can be calibrated to be more accurate (e.g. oh shit! it says 5feet when it should say 0)

RemoteControl

------------------------------------------------------Prostart----------------------------------

Automaticallyswitches to speed and heading after start sequence finishes

Distanceto line bar graph (though I have to comment, each bar segment is equal to 10mnot ft.)





III. User Friendliness

Thisis Velocitek's real point of departure. Though the veloicitek clearly does nothave as wide an array of types of information, and display combos, and specialfeatures/tools, it does seem to be much easier to use, simply because, well, itdoesn't have as much info and special features to sort through! I especially likethe fact that it switches into "race mode" (speed and heading) automaticallyafter the sequence is up, meaning I don't need to screw with it when I amfocusing on the race.

However,I do think it is of note that the Rockbox does make up for it's lack ofsimplicity in some part with its remote control. I would think the value ofthat remote control is probably directly linked to the intensity of the boatyou sail. (e.g. REALLY helpful on a trap boat)

IV. Price

Prostart,with mast bracket 658.00

RockBox, with mast (strap) bracket 711.00

Sowith brackets, the rockbox is 53 dollars more. I haven't figured in shippingbecause that depends on your proximity to either manufacturer.

V. Overall Opinion

Let me start by saying I haven't used either ofthese, so this is more or less speculative. I will say though that I want toget as much capability for my dollar, as possible. Velocitek has chopped off a lot of differentfeatures. They justify this by basically appealing to the usage habits ofprofessional sailors.

"Theability to use GPS data to estimate real-time VMG is undoubtedly a cool featurethat appeals to many sailors. Nevertheless, when we did our homework for theProStart we were surprised by the fact that we couldn't find a singleprofessional sailor who looked at the VMG on their SC-1 while they were racing;every last one of them preferred to see speed and heading."

AND

"We startedout by carefully observing how pro sailors use GPS instruments. We keptall the features that the pros were actually using and eliminated everythingelse."

So in asense, Velocitek is touting its lack of types of information as an asset, inthat it ensures simplicity.

---I haveto say though, that at the end of the day, (opinion!) I would like to be theone that makes the determination of what I do and do not use, and a variety ofdifferent options (what type of info, how it's displayed) is appealing to me.

As for userfriendliness, I think it's fair to draw an analogy to these new smartphonesthat are coming out. They have phones with everything from internet, and weather reports to mp3 playersand gps navigation. When I got mine, it took awhile to get the hang of it, butonce I did, I could sort through everything with blazing speed. Granted I am23, and texting/cell phones is fast becoming my generation's form of communication, but I digress. I think that the hindrance of the rockbox's functionality can be overcome with familiarity with using the remote and swicthing through the menu screens.



Plus, the rockbox comes from Detroit, and they need all the help they can get.

#8 Vernon Green

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Posted 15 April 2011 - 03:38 PM

I Don't have a prostart but I do have both Velociteks other products. you really can't beat the customer service of the Velocitek guys.

#9 E-quilibrium

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Posted 15 April 2011 - 04:10 PM

whoops, the rockbox has 30 different information display combos, not 27... sorry!

#10 ursus

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Posted 15 May 2011 - 01:22 PM

Rockbox for sale at $420 obo:
http://www.sailingan...ed/gear.htm#ele

#11 xyzzy

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Posted 15 May 2011 - 06:04 PM

Broadcom provides a software library that realizes the GPS navigation solution in the host using minimum resources and with no real time requirements.


Lack of real time requirements for the host doesn't mean anything bad about the GPS chipset. All the "good" GPS chipsets probably say the same thing. It just means the chip is a little smarter and does more of the GPS calculations itself and has buffers so the host CPU doesn't need query it thousands of times per second to avoid losing data.

#12 Sailabout

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Posted 16 May 2011 - 07:18 AM


Broadcom provides a software library that realizes the GPS navigation solution in the host using minimum resources and with no real time requirements.


Lack of real time requirements for the host doesn't mean anything bad about the GPS chipset. All the "good" GPS chipsets probably say the same thing. It just means the chip is a little smarter and does more of the GPS calculations itself and has buffers so the host CPU doesn't need query it thousands of times per second to avoid losing data.


What you need to know is how many channels the reciever has and how fast it runs to know if your speed update is a guess or fact every times it changes.
You also want to know if you are reading any waas data to make that speed output is very accurate or not and postion for vmg
Look up GPS accurancy which is in distance but averaged to a percentage over time.

#13 micha571

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Posted 31 August 2012 - 03:03 PM

How high are the digits in the display of the new rockbox? Couldn't find any info on this.

#14 Ultraman

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Posted 31 August 2012 - 04:25 PM

I recently got a ProStart to replace a 4 1/2 year old SC-1 that was no longer working.

Similar functionality to the SC-1, but the UI and case is so much better.

There is a reason the AC45s are using Velociteks...

#15 Vela Sailing Supply

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Posted 01 September 2012 - 10:43 PM

Rex,

Both products are very good and dome from respectable houses. Pro Start has a very KISS approach which is a good thing. Rockbox offers good features such as the vertical/horizontal display that may sound simplistic but solves a lot of problems for some buts that don't have plenty of room. Also the SD card seems to be good for some users together with the remote. The Pro Start has the nice line feature as well as the other standard features present on Velocitek products.

What boat is this for?

Feel free to drop me a note and we can over options and price. There is always a deal for an SA'er. :)

#16 ccp_merc

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Posted 07 September 2012 - 04:49 AM

I have just released an iPhone/iPad app that records video and puts your gps speed (and angle of heel, direction etc) directly onto the video. It will also display this information real time onto the screen. You do need to waterproof your phone before you use it on a small boat (I use a Lifeproof case).

Here is an example of a a video I took of us sailing our fireball last weekend.

http://www.youtube.c...h?v=0RwSZPHhwXE

The application is called VideoProof and is available on the app store if you want to check it out.

ccp




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