What is this?

[tchpet2]

Hi all,

I am not sure this is the right forum, but can someone tell me what this thing is and what it is for? It is at the transom of the boat (1995 Lowe 170 Bass Boat) on the right side. It hangs below the boat and "pivots" (like it is a switch or something). There are no wires attached to it.

I am new to boats and this one is brand new to me. The thing catches tons of weeds and I am ready to either remove it or cut off the part that hangs below the bottom of the boat. However, before I do, I want to make sure that it doesn't have a purpose that I am missing.

Thanks,

 

[_chris_]

Re: What is this?

That is the pick up for your speedometer. When pushed towards the stern it should lock into place and stay there otherwise it is not working properly.

EDIT: I just looked at your picks and it looks to be missing the tube that comes off of it. and maybe the nipple broken. You should have atube that runs from that dohicky all the way to the speedo. If it is broken you can get a whole new gauge including that part and tube for somewhere around 50 bucks new.

 

[Thad]

Re: What is this?

It still will not work. There is to be a rubber "vacuum" hose attached to it and the other end to your speedometer.

 

[Huron Angler]

Re: What is this?

Previous post is absolutely correct...that is known as a pitot tube used to measure air/water pressure in order to determine speed. I've heard that they are considered to be more accurate than GPS or the spinning wheels that are also common.

link to more info http://en.wikipedia.org/wiki/Pitot_tube

 

[ezmobee]

Re: What is this?

are you sure you didn't mean less accurate?

 

[tchpet2]

Re: What is this?

Interesting...........I thought the thing on the other side that looks like a wheel was for the speedometer.

Either way, the speedometer doesn't work and now I know why. Although with a 25hp, it really doesn't matter anyway

Thanks!

 

[Thad]

Re: What is this?

Either way, the speedometer doesn't work and now I know why. Although with a 25hp, it really doesn't matter anyway
Thanks!

No, it does not matter, but, you have the gauge and rubber tubing is cheap. Why not hook it up.

and correct, it is LESS accurate.

 

[gonefishie]

Re: What is this?

Previous post is absolutely correct...that is known as a pitot tube used to measure air/water pressure in order to determine speed. I've heard that they are considered to be more accurate than GPS or the spinning wheels that are also common.

link to more info http://en.wikipedia.org/wiki/Pitot_tube

Unless you have old, not working correctly GPS, I can't think of anything more accurate then GPS. Maybe was a home made mouting arm for speedo wheel. Get rid of the fugly thing, you won't miss it.

 

[tchpet2]

Re: What is this?

So why would I have the wheel and this thing? The wheel on the other side is missing the wire.

Could the previous owner tried to convert it over? And if so, how will I be sure that the gauge hasn't been changed out?

It would be nice to get it hooked up, but I don't want to go through getting everything if it won't work with the guage I have.

 

[ezmobee]

Re: What is this?

Interesting...........I thought the thing on the other side that looks like a wheel was for the speedometer.

Either way, the speedometer doesn't work and now I know why. Although with a 25hp, it really doesn't matter anyway

Thanks!

The wheel is for the speedometer feature on your fishfinder.

 

[tchpet2]

Re: What is this?

Oh..........no wonder that doesn't work either

 

[pmat1]

Re: What is this?

It is possible the owner had a regular ol speedo and a fishfinder with a speed sensor.

 

[Huron Angler]

Re: What is this?

are you sure you didn't mean less accurate?

ummmm...oh yeah I meant LESS accurate. Thanks for keeping me honest

Truthfully we used to have a spinning wheel type and I always thought it was more of a ballpark measurement and that the pitot tubes WERE more accurate.

For GPS I've seen both good and bad, the newer ones do seem to be pretty good for speed.

 

[IVAZ]

Re: What is this?

ummmm...oh yeah I meant LESS accurate. Thanks for keeping me honest

Truthfully we used to have a spinning wheel type and I always thought it was more of a ballpark measurement and that the pitot tubes WERE more accurate.

For GPS I've seen both good and bad, the newer ones do seem to be pretty good for speed.

GPS is not 100% accurate all the time is why. It depends on the number of satellites and their current location. 3 satellites almost directly above you equals a garbage reading. 3 satellites far apart equals the best reading. The reason most of the time it works great is because you can almost always be in the range of six satellites. Some land surveying units won?t sacrifice accuracy so they will only work when they connect to at least 8 satellites. The marine GPS units work off of cell phone towers so you can guess how well they work when you?re out of range from a cell tower.
We use GPS units to mark locations, most of the time you can get within 0.01 accuracy other times within 100'. GPS is not considered accurate. If property corners are set with it in Texas, by law you have to check it by conventional methods. Elevation measurements are even less accurate than horizontal measurements.
With that said, it?s still better than a pitot to measure speed.

 

[Mike Robinson]

Re: What is this?

... The marine GPS units work off of cell phone towers so you can guess how well they work when you?re out of range from a cell tower...

Huh? This statement confuses me. Please explain.

 

[5150abf]

Re: What is this?

I agree, how can that be?

So if I have a marine GPS and get 10-15 miles from shore it will stop working?

How do ships navigate across open ocean thousands of miles from a cell tower?

 

[IVAZ]

Re: What is this?

There is other units that dont require cell towers. They start at around $80,000. (leica, Trimmble, and Nikon make the expensive units you see on 18 wheelers and offshore boats)

 

[IVAZ]

Re: What is this?

And yes, you won?t get a reading if you?re out of range from a cell tower. Have you noticed that GPS Speedos don?t measure right away when you first turn them on? They are actually dialing up with a tower. The triangulation that measures speed is based on the tower, the GPS unit and one satellite. It will instantaneously check itself with other satellites but it only really needs one. 3 is about the minimum any will use though. The redundancy is what gives it any level of accuracy.

EDIT: I missed one part. The unit signal first goes to a GPS base station, then it goes to a cell tower.

 

[_chris_]

Re: What is this?

Why would they do that with a marine GPS but not my $80 handheld that works everywhere? It doesn't make any sense to me.

 

[gonefishie]

Re: What is this?

Are you sure about that? There are many many times when I get no bar at all on my phone but the GPS still took me to the saved waypoints. My graph acquires 6 (I think) sat signals. For some reason, it can't get any signal while in my garage but my phone gets 5 bars.