What is this hose?

[aharl]

I'm pretty new to boating and outboards. I noticed this hose when putting the transom saver on earlier this week.

What is this and is it ok just dangling. This is on a Mercury Optimax 75. Apologies if there is a thread that already has info related but I've tried searching around the internet but I'm not even really sure what I'm searching for.

 

[jimmbo]

it goes to the Speedometer, the end your holding likely came off of the fitting on the top of the gearcase. It looks like it got pinched as well.

 

[bigblocksarefun]

You might have enough slack to pull out and down to reconnect it to the lower unit.

 

[jimmbo]

You might have enough slack to pull out and down to reconnect it to the lower unit.

Still wouldn't work, the hose has a hole in it.

 

[airshot]

Those pressure speedometers are not very accurate anyway, far better results on your gps. Mine doesnt even read until you reach 20 mph, looks good on the dash though!!!

 

[jimmbo]

GPS has inherent Errors for watercraft as it is measuring speed across the bottom of the lake, not speed across the water.

 

[aharl]

Thanks all! This was incredibly helpful. Eased my mind also. Honestly the speedometer hasn't worked since I bought the boat earlier this year and I've been using the GPS anyways. Great to know why now

 

[airshot]

GPS has inherent Errors for watercraft as it is measuring speed across the bottom of the lake, not speed across the water.

???? GPS measures time and distance across a grid on earths surface whether water or land. Being on the water should have no bearing on the distance and time traveled.

 

[jimmbo]

Any where there is a Current, the GPS will be off in both directions, as it is not taking the speed of the water into the equation. if the current is 6 mph, and the water Speedo is saying 20 mph, in one direction GPS will say 26mph, and going the other way, it will say 14mph

 

[Silvertip]

Any where there is a Current, the GPS will be off in both directions, as it is not taking the speed of the water into the equation. if the current is 6 mph, and the water Speedo is saying 20 mph, in one direction GPS will say 26mph, and going the other way, it will say 14mph

Throw out your anchor in a stream with a 6 mph (or any speed current). Look at your pitot speedometer and it will show what the current is -- not your speed because you are not moving. Now break out your GPS and it will show zero mph as it should. Underway if your gps shows you are going 20 MPH you are doing 20 miles per hour whether upstream or downstream. If you rely strictly on the pitot speedometer showing 20 mph as you travel downstream with a 6 mph current then yes -- you are traveling 26 (minus drag). Conversely going against that current with an indicated 20 MPH you are going 14 mph. Either way, GPS will show 20 MPH when you are going 20 MPH upstream or down.

 

[flashback]

Reminds me of the old cartoons
Popeye struggling at the helm but still going backwards...

 

[jimmbo]

Throw out your anchor in a stream with a 6 mph (or any speed current). Look at your pitot speedometer and it will show what the current is -- not your speed because you are not moving. Now break out your GPS and it will show zero mph as it should. Underway if your gps shows you are going 20 MPH you are doing 20 miles per hour whether upstream or downstream. If you rely strictly on the pitot speedometer showing 20 mph as you travel downstream with a 6 mph current then yes -- you are traveling 26 (minus drag). Conversely going against that current with an indicated 20 MPH you are going 14 mph. Either way, GPS will show 20 MPH when you are going 20 MPH upstream or down.

GPS will show water speed plus the current in one direction, 20+6 so 26mph, and in the other, boat speed substract the current, 20-6 so 14mph

 

[airshot]

GPS will show water speed plus the current in one direction, 20+6 so 26mph, and in the other, boat speed substract the current, 20-6 so 14mph

Cant say that is true, just had my new to me boat out on the river doing some testing and getting familiar with things. Current was rolling pretty good but not affecting the gps in any way. Yes your boat will go quicker with the current and loose a little going against it, but that is due to resistance or lack of whether going with or against the current. The gps has no idea whether you are in a current or not, it only measures the time and distance you are traveling

 

[jimmbo]

Current doesn't roll. It is simply water flowing

 

[racerone]

GPS shows speed over the bottom.

 

[jimmbo]

GPS shows speed over the bottom.

A concept that a lot don't understand.

 

[bigblocksarefun]

Still wouldn't work, the hose has a hole in it.

It wouldn't after cutting that portion off.......my bad, didn't think I'd have to specifically spell out that part smh

 

[airshot]

A concept that a lot don't understand.

Me either, a gps does not depend on elevation, only time and distance

 

[jimmbo]

Even changes in Elevation, as in going up and down hills will result in Inaccurate Speed Readings. Simple Geometry will show why that will occur.

 

[dingbat]

Even changes in Elevation, as in going up and down hills will result in Inaccurate Speed Readings. Simple Geometry will show why that will occur.

I could see that being true if GPS wasn't 3 dimensional.