KenD

Prior to the start of the St. Cloud race, SBI/APBA Chief Inspector Ritchie Dancisin instructed all P-Class competitors to set their Garmin GPS system to take a track reading every 3-seconds instead of every 50-feet as previously prescribed in the SBI/APBA rulebook. This change in procedures addresses a reduction in the number of trackpoints certain approved GPS units can store in memory.

The 3-second interval allows for a minimum over two hours of recording time before the GPS unit starts to overwrite previously recorded track speeds. It also helps to eliminate “spikes” in the recorded speeds due to GPS signal shifts and other extraneous factors.

An added bonus to the change in settings is uniformity to way GPS recorded speeds are used to determine breakouts. Now, both SBI/APBA and OPA are both using the 3-second interval during their post-race Inspection process to determine the official race results.

It is the Team's responsibility to install and setup their on-board GPS systems to record speed and course track information during a race. SBI/APBA recommends a second backup system in case of failure of your primary system during a race. Without accurate recorded GPS data, there is no way to verify your placement after the race.

Remember guys…keep your eye on your speed…but it's what's in the box that counts!

Wazzup Racing

Nicely done guys. By the way. I heard we missed a great time. Smitty

bryanh

Hey Ken I went and bought all the stuff I need and now I will need your assistance in making it work.

KenD

Bryan,

I heard you went to West marine with a shopping list. I will be happy to help you get everything set up.

With some of the recently announced technology, you can now track your favorite team in real time on your cell phone. Its a free feature on specific Verizon phones. Shows your location and speed on a map, with updates every 10 seconds.

Next thing you know, we wont need to download data. All the boats will be tracked around the rascecourse in real time by Scoring on their laptops.

The technology is avalible...we just aren't using it...yet.

FunHome

Awesome!! A step in the right direction to uniformity!!!

fastedy

What are the minium requirements for the GPS, what units do you recommend?

Eddie

Xtremeracing

I'm not sure but i think the units that OPA is using now might work . I know OPA and SBI are looking at that now.

Wazzup Racing

We have agreed with JC, OPA can use our system, and SBI will use theirs. After all we are just down loading GPS info. I will be attending a few SBI races and will bring a couple of our units with me to test against the SBI units. Smitty

MIAMIBOYZ

Bring them to Miami so the spanken can begin, you wont need a GPS in Miami. We miss racing against you knuckles heads!!!!

KenD

As I understand it, the OPA GPS unit was designed to monitor commercial trucking operations and the system simply records GPS data. It does not provide a display for the team to monitor their speed during the race. I also understand that the OPA system is stored in a box located somewhere in the boat during the race and the data that is recorded is collected and read after the race….similar to the old GPS system used by APBA. I am assuming that OPA teams use some brand of GPS mounted on the dashboard of their boats to monitor their speed during races.

The Garmin GPS units that are approved by SBI/APBA are permanently mounted on the dashboard where the crew can monitor their speed during the race by watching the screen display. The GPS antenna is mounted (or should be) with a clear view of the sky. It locks onto 12 GPS navigational satellites which provide the maximum accuracy for location and speed calculations.

The Garmin units record tracks (also referred to as breadcrumbs), which is data files of the boat’s GPS location and speed at various points during the race. These tracks are data files recorded on an internal flash memory chip that can be downloaded to your computer. Track data is downloaded by SBI/APBA Race Officials after the race and reviewed to determine if a breakout condition occurred. Recorded track data is used because it shows the boat’s location and speed during the race. Setting the time period for recording trackpoints to 2-3 seconds filters out most “spikes” normally caused by variations between signals received form different satellites…similar to passing a cell phone call from one tower to another.

Max speed, which is a feature displayed on the GPS unit’s monitor can not be trusted to determine if a breakout occurred…even my 6 year old nephew knows how to reset max speed on the fly. Resetting max speed displayed on the monitor has no effect on the data stored in the unit’s memory. That is why the downloaded data files are used by Race Officials to determine if a breakout occurred. You can’t cheat the data file numbers.

The recording parameters on the Garmin can be set to take a track reading anywhere from once every second to once every so many hours. The unit calculates time over distance traveled from each recorded point and gives a speed for the distance traveled between the recorded points.
The more points you record, the more accurate the recorded speeds. The Garmin units operate at around 100 kH, which allows them to calculate 10 points per second. This is overkill for the purpose of generating a track of where the boat has traveled (remember these units are designed as navigational aids...not speedometers), so Garmin allows you to record a maximum of 1 point per second. A boat traveling 100 mph is traveling 147 ft per second.

One interesting thing about a Garmin unit is that it does not display or record speeds over 100 mph in tenths of a mile per hour. This is the reason a lot of boats running close to 100 mph sometimes have a hard time getting over the 99.9 “hump”. This has something to do with the proprietary algorithms used to calculate speed…since the unit can only display 3 digits, it apparently uses two different algorithms…one for speed under 100 mph when it displays and records speeds in tenths of a mile per hour…and another for speeds 100 mph and over, where speed is displayed and recorded in whole numbers. Because of this, the units will “round up”…when true speed reaches 100.5 mph it will display and record 101 mph. and round up again when true speed reaches 101.5 mph.

I’ve checked and verified this using live NEMA data recorded from the Garmin unit (another feature of the Garmin unit…but I won’t get into that) and a data logging system that I have that records GPS speed ten times per second. The bottom line is that if you are running in a Class with a breakout speed over 100 mph…your unit will show that you reached max Class speed .5 mph before you actually got there but won’t show a breakout unless you go more than .5 mph over your breakout speed…you get an automatic .5 mph buffer before the unit will record a breakout if your running in P2 or P1.

The Garmin units can also record track points based upon distance traveled and by changes in heading. Using these parameters does not give nearly as accurate speed information as setting the unit to record by time.

The SBI/APBA approved Garmin units are models 172 and higher. These units have a card slot that Race Officials use to download the recorded data to a memory card. This card slot also allows the owner to upload detailed maps, predetermined routes with waypoints, and previously recorded tracks which can be used for navigation.

You can buy a program from places like West Marine to download the data recorded by your Garmin unit to your computer. This program allows you to do a variety of things, i.e. view your recorded tracks, review speed between track points, and show waypoints on a map included with the program.

There are some other really neat things you can do with data recorded on the Garmin units after it is downloaded to your computer. Garmin track data files can be imported into other programs. If you click on the link below you can watch a replay of the data we recorded during the 2006 New York race and loaded into a program that recognizes downloaded Garmin track data:

http://www.magnalox.net/log/no.php?f...=New+York+Race

So, to answer your question on which unit I would recommend…I would say get any one of the SBI/APBA approved Garmin units....they are all the same for what we are doing with them. If you are racing in OPA, you will be using their GPS system for scoring, but you will also need something to monitor your speed during the race. If you get an approved Garmin unit and you decide you want to run an SBI/APBA race you will already be set because you will have both your monitor and your data recorder.

Prices for Garmin units vary, depending on the specific unit you decide to buy. The best deals can be found on eBay. Most of the monochrome GPS units that are being sold on eBay are there because the owner wants to upgrade to color. Functionally there is no difference….they all do the same thing and have the same features. You can also find some pretty good deals on refurbished units on eBay.

Garmin supports all models by allowing owners to download firmware upgrades from their website….even the discontinued models. I have an 8 year old Garmin GPS III+ (a small pocket model) that I keep up-to-date with the firmware updates, it works just a good as the 182C we installed in the race boat two years ago. I can download the track data from my III+ to my computer with a cable…we use it as our backup system in the race boat.