Wearing the Motions

I thought I would put a few pictures and ideas together that might be helpful.

My original experience with the first model Motion was a mixture of excitement and devastation.

Excitement because testing revealed that it was, in many ways, the very best GPS device I had seen by quite a large margin. 10Hz, multi- GNSS, with exceptionally well thought out software and user interface, and very accurate, consistent and clean results.

Devastation, because just as I was getting really attached to it, I lost it in a high speed crash at over 40 knots. It came out of the neoprene arm band and sank. I spent hours crawling along the shallows searching for it with no luck whatsoever.

Julien was just as surprised as I was, and immediately offered to replace it. He also initiated a redesign of the body to include slots for a strap and a new armband to prevent separation.

It took some considerable time to get the replacement for reasons well documented elsewhere in these forums, but true to Julien's word, it eventually arrived a couple of months ago. It was my off season for sailing so it has not had much time on the water, but I have tested it skiing and Motorcycle riding and it has proven to be excellent. The only practical difference from the original design is in the software, which needed to be redeveloped for the new build and does not yet have all of the features of the original. Julien assures us he will gradually add those features through firmware updates as he catches up with a large queue of backorders and gets the time to get back to software development. In the meantime, it has all the basic features to allow it to be very user friendly for most windsurfing purposes.

Here are my thoughts on wearing them:

My highest recommendation is to find a way to wear it/them (and any other) gps on to top of your head. The reason is simply that this gives it the very best possible sky view (satellite view) for best reception of the maximum number of satellites received. I have done a huge amount of comparison and experimentation with this over the last 14 years with various devices starting with the GT-11 and GT-31, and the evidence is really clear. That position produces the very best results. ie. The most reliably trustworthy data.

Here is the same helmet I have been using for all those years. It is a Protec action sports helmet, with the advantage of a thick enough foam shell to accomodate a cavity that was originally sized to hold two GT-11's. It easily holds two Motion LCD's with room for extra foam padding between the devices and the top of my head, and even more easily holds the two Mini Motions that I have been using for a couple of seasons now. Just for convenience, I put the Mini's in a ziplock bag, but there is really no need for any waterproofing as there was with other devices. I use a few blocks of old flexible lifejacket foam to pack them in place.





Two Mini Motion Loggers and some foam padding in zip lock bag:


Folded and packed into helmet:


close up:


NOTE: They need to be mounted with the antenna side against the plastic shell of the helmet! The plastic shell does not bock the radio signals.

Here are two LCD Motions inserted in the cavity with the screens against the shell and packed in with the blocks of foam. I will place a sheet of the same foam over them under the liner in actual use:


A close up of the same. NOTE that they are jammed at an angle to each other which effectively prevents the buttons being squeezed by the pressure holding them in place.



And here with the lining tucked back in to cover them as I use it:



I will wear them this way for testing and comparison, but since they are LCD Motions, they are better worn on the Bicep where they can be read. I plan to continue to use the Mini Motions in the helmet for normal use.

Now, I understand that this method wearing is a stretch too far for many users, and it is true, and my testing confirms, that quite reasonable data can be obtained from wearing your device on the Bicep in the windsurfing situation. That is definitely the next best location. The Motion LCD and Mini loggers come with arm straps to facilitate this and work quite well.

The only problem is that it is still possible for the device to become dislodged and lost off your arm in a big crash. The Motion devices don't float, and neither of the arm bands has enough buoyancy to make tham float, so some other strategy may be required if you want to be completely safe.

The obvious one is some sort of tether string attached to your wetsuit, impact vest or harness.

Here is the arm strap that comes with the new LCD Motions:




The arm band strap threads through a plate with slots on the back of the device body and through the neoprene padding.



Below is the original LCD Motion arm band. It held the device in a moulded rubber piece. The GPS was inserted in through an overlapping flap on the back. We thought there was no way for the device to come out of it, but I was proved wrong when, in the high speed crash, the arm band rolled down my arm, exposing the slot on the back and somehow enabling it to be ejected that way. I have modified it by cutting two small slots in the backing material to allow an extra strap to be passed through which should prevent it being ejected.This would be safer, but would still need a tether in case it came off the arm altogether. I tested this in the kitchen sink to see if the extra neoprene would allow it to float, but it did not. I am pretty sure it would be much slower to sink if it came off though, and should be reasonably visible in clear water.







Here is my better solution that is probably a little more secure on the arm, and definitely does float - tested in the Kitchen sink!

This is the same H2Oaudio arm bag I use for my android phone for on the water feedback with the GPS-Logit App. It will actually hold two LCD Motions and easily hold two Mini's. It says on the arm very well and is very resistant to slipping around to under the arm.









I feel bound to point out yet again, that wearing the GPS device on your shoulder or in your vest, or especially under your wetsuit is a very bad idea indeed. Wet materials very effectively block radio waves leading to poor reception and a high likelihood of errors, or even unuseable data. And in such positions, the antenna usually also has a very poor sky view to further compound the problems. The problem with on the shoulder is that it is very close to your head, which effectively blocks it's view from a large sector of the sky. It's usually not as bad as in your vest, or under your wetsuit, but comparison experiments show it sees less satellites and has more significant errors.

Great post Sailquik. I too love my Mini, terrific, compact, easy to use device. I experimented with flotation and found if I weaved my strap through some 3mm EVA foam it would float. Trouble with that was it got in the way charging. Next problem, which is common to any gps you strap to your arm, is the tendency for the device to rotate under your arm.
that was pissing me off, so I now resort to either my vest shoulder strap (yes, naughty boy.) or my Gath helmet. I thought about housing it inside the helmet, but was concerned that with the thinner foam the gps could injure my head in a stack. So lazy me just strapped it to the top of my helmet via the existing helmet slots. I did glue some EVA to the top of the helmet for it to sit on. Problem with this method is: 1/ gps is vulnerable to damage from your mast; and 2/ it ain't no fashion statement!

Again I say."Problem solved!"

Please tell me more about this rubber pad on that other armband? Pictures and all. The bottom of my armbands serve no function whatsoever so I could replace them with anti-slip rubber or whatever it is.

I didn't read the whole thread but if you can, don't add anything around the devices, especially not in close proximity to the top of the Mini's. The whole top surface is the antenna. They're waterproof!

A bit surprised to see all this modifications to helmets, i personally don't do any modifications to this kind of safety devices after i've read the story from Michael Schumacher where the GoPro Mount had a devistating impact after a relative small crash on a slope (-> www.mthigh.org/Articles/GoPro-camera-aggravated-Michael-Schumacher-accident.pdf )

Can someone please advise if the mini motions are waterproof or do they need to be in a waterproof bag. Cheers

In fact Julien says, "Do not put in a bag, it only degrades the signal". That's why it's fully sealed.