Webcam in the Mast

[svpresent]

We're planning to go upriver in the Guadiana in Portugal. The cruising guide dated 2010 says the bridge has a clearance of 23 meters at low tide. This means I'll have 0,4 meters room so my vhf antenna will be bending, which it can. Of course we'll go at springtide and with still water and so on but it will be somewhat unnerving. I was thinking of mounting a wifi webcam in the masttop to help me relax. Anybody here who did that before?

Does a wifi webcam communicate with a laptop right under it?
I was thinking of adding a sort of crosshair: a thin horizontal wire levelled with the lens on some 15 inches distance. This would enable me to see if I have enough room when still 10 meters away.

I was also thinking of these laser-operated distance meters but these are much more expensive than a wireless webcam.

I'll appreciate any sort of advice.

Cheers!
Len.

[daddle]

I'd trust the chart and go at a minus tide. A curb feeler kinda thing might be a low-tech way of testing the height.

I'd go real slow. If the current is dragging you under do it backwards in dead-slow forward gear.

Or...Anchor nearby. Walk out on the bridge with your leadline. Mark it first with the mast height.

[DeepFrz]

Fill a few 5 gal. jugs with water, suspend them using the main halyard and hang them over the side. Guy them fore and aft. They will heel your boat and give you a little extra clearance.

[osirissail]

As others have mentioned you do not need to get involved in such high tech. Besides which a boat is not a very stable platform so as the boat bobs and rolls the "reference mark" will be all over the place. Masts tend to sway even in really calm waters as your turn the boat.
- - Daddle has the best advice both for measuring exactly what the bridge height is above water and also to approach an "iffy" clearance situation at dead slow making allowances for any current flow.
- - For mast height you can tie a tape measure to a masthead halyard and then haul it up to the top. Then hang it over the side to water level to get a measurement. Add to that measurement what you think you need to add to get to above the masthead cap and anything mounted up there like lights and antennas.

[oldjags]

Originally Posted by daddle

I'd trust the chart and go at a minus tide. A curb feeler kinda thing might be a low-tech way of testing the height.

I'd go real slow. If the current is dragging you under do it backwards in dead-slow forward gear.

Or...Anchor nearby. Walk out on the bridge with your leadline. Mark it first with the mast height.

I think the last suggestion is questionable. It's really hard to tell how much bridge structure is under you when you're standing on top of the bridge. You just can't see it when your view is blocked by the roadway and railings, etc. You can measure from the roadway to the water pretty easily, but how thick is all that supporting structure?

I could see a gimballed, self-levelling camera at the mast head being of some use. If you mounted it out in front of the mast, it would also serve as a sacrificial tell-tale to let you know in time to save the mast.

[MehmetCan]

Although I'm a huge fan of every kind of electronics, I can see several problems with the webcam solution you ask right away.

1. As osirissail points out, the camera will be all over the place because of the swing of the mast.
2. Most webcams have wideangle lenses, which makes them unreliable to measure things by just looking at the screen.
3. My wifi connection gets psycho even when I run the microwave oven. Now try to imagine it with a radar dome, VHF antenna and all the other kind of electronics running while using it. I don't know about you but VHF or radar are far more important for me to run constantly during a tight situation than a webcam.
4. Either you use bluetooth or wifi, the webcam will still consume energy, which means you either should run a wire for it or climb to the top of the mast every other day and change the batteries. Run the power wire, it'll include a more reliable type of connection anyway.

All being said, having a webcam up the mast is still a fun idea, but it should stay as a "fun idea" only.

What I would offer is pretty simple, attach a thin wire or piece of wooden stick on top of the mast horizontal to the ground. Go dead slow, if it touches the bridge, well, 5 gallon buckets are your best friends!!! Enjoy your trip.

[MehmetCan]

Or another solution...

Invite that annoying family you know and their most annoying kid on board. Ask him if he had ever touched the bottom of a bridge, then yank him to the top of the mast to do so!!!

[HopCar]

I wonder if something like this might be useful?
Two Loons Trading Company,Inc.

[daddle]

Originally Posted by oldjags

I think the last suggestion is questionable. It's really hard to tell how much bridge structure is under you

Yeah that was a stretch...ok....a helium balloon from the deck.....

[osirissail]

The Reinke 15m has a 21 meter (69 ft) mast from data from: Reinke 15 M used boat for sale. The Yacht Market online boat sales and charters.
- - You give the bridge at 23 meters (75-1/2 ft) so you should have 2 meters (6-1/2 ft) clearance - so what is the problem?
- - Only if the tidal range in that part of the river exceeds 2 meters should you have a problem?
- - Mounting equipment such as a webcam that is designed for interior use will normally result in the rapid failure of the equipment due to rain or salt air contamination.
- - If you are planning on mounting the webcam on top of the mast then you should have no problems while you are up at the top of the mast measuring the exact height of the mast above the water.

[stillbuilding]

Ok, so maybe no problem with this one bridge but interesting issue. Couple of solutions;
First is simple. Distance off bridge can be obtained from chart or sextant if pylon width given, even accurate distance off meter and then can use sextant to calculate bridge lowest height.

Second is to mount a laser level at the mast head. Cheap as chips in DIY home shops and should be useful even with the mast swinging. Have not tried it but should work I think. Can always use it for future home projects if not useful!

[osirissail]

I suspect that anybody asking or suggesting these "hi-tech / laser / sextant" devices on a cruising boat have never done any serious long term cruising. It is all so much overkill, impractical and failure prone that such things would never be used or contemplated in real life by an actual cruiser.
- - You have charts for data on bridges, etc. You have measured your mast to water line distance. You have binoculars to check out any sign boards on the bridges. You have the common sense to approach any doubtful bridges at dead slow and are prepared to reverse back if necessary.
- - That is all that is necessary and cruisers have been getting under bridges just fine using common sense and some caution.

[stillbuilding]

Originally Posted by osirissail

I suspect that anybody asking or suggesting these "hi-tech / laser / sextant" devices on a cruising boat have never done any serious long term cruising. It is all so much overkill, impractical and failure prone that such things would never be used or contemplated in real life by an actual cruiser.
- - You have charts for data on bridges, etc. You have measured your mast to water line distance. You have binoculars to check out any sign boards on the bridges. You have the common sense to approach any doubtful bridges at dead slow and are prepared to reverse back if necessary.
- - That is all that is necessary and cruisers have been getting under bridges just fine using common sense and some caution.

While I generally agree with the practical low-key approach (cruised a bit myself) on one occasion at least I had to resort to the sextant. Was sailing near Singapore and was confronted with new and undocumented bridge. Not on my charts and did not have updated NTM. Found the sextant quite useful for calculating heights.

[nigelmercier]

You could go though at full speed, so the stern drops into the trough at the end of the bow wave. Wouldn't like to do it though

[ggray]

Late to this thread , but I find it very interesting, as I have been thinking about doing the same thing for some time. I have a cat, so the heeling idea won't work for me.

I was looking for a wireless camera that I would hoist to mast head when needed. Would also use the camera mounted forward to help weighing anchor when single handing. These cameras are made for outdoors, so should work fine. What I'm really wanting is to be able to display on an IPad,but don't think we are there yet.

Anyway, I picked up one of the trailer hitch guiding cameras (could be helpful for that purpose anyway), but it differs from what was previously posted in that it mounts right to the hitch rather than above looking down as I surmise the other was. We gave it a trial run (i.e., just hand held in place) and we realized that the camera produced a mirror image! Might help when backing up, but not for this, so back to the drawing board. I'll check this other hitch camera.

Normally, I'm not into all the bells and whistles. I use a GPS to tell me where I am and where I want to go; no routes and other things. But I would like a little tech stuff here as my mast height is a little over 63 feet, not including $instrument$, and I've seen too many 65 ft bridges that aren't that, and poorly calibrated or non existent height boards. Thought this might be worth looking into.