River Guadiana air draft

P

Peter Morgan

New Member
Joined
27 Oct 2020
Messages
22
Visit site
To anyone who has been up the river. Looking for 2 air drafts. One, for the bridge, have seen quoted 18, 20 and 21 m which is correct?
The second, there is a power line across the river midway between Alcoutim and Pomarao. Have seen nothing on any charts pilots etc which refer to this power line. Any clues on air draft.
Boat air draft 19m
 
Tried to find an exact answer to this question a few years ago when we passed through and the information varied between 15-20m. Nobody seemed to know the truth or could agree on the state of tide their measurement was for! We got our 17m stick through at low tide twice without touching the antenna. It looked close from the bottom, but then it always does :)

Climb up the mast if you're worried. You can finally figure out and document the truth! Also, try passing in the middle of the span for maximum clearance.

Don't recall any power lines to worry about, did they sprout recently or just really high up?
 
Haha, the 'power line' is a zip wire! The planning consent for the zip wire was that it shouldn't have an air draft less than the bridge. If you can make it under the bridge you can make it under the zip wire.
We have been under the bridge with 21m air draft. Can't remember the state of tide
 
A friend measured the bridge at 23 m low tide.
Alcoutim to Pomarao would be a stretch, San Lucar to Alcoutim has a time travel international zip wire.
 
Peter Morgan said:
To anyone who has been up the river. Looking for 2 air drafts. One, for the bridge, have seen quoted 18, 20 and 21 m which is correct?
The second, there is a power line across the river midway between Alcoutim and Pomarao. Have seen nothing on any charts pilots etc which refer to this power line. Any clues on air draft.
Boat air draft 19m
Click to expand...
23 mtrs
 
I think that I've posted this before. I've been through with my boat and measured air draft as 19.8m. The height of the zip wire is much higher on the Spanish side and did once go under it closer to the Portuguese side. Clearance will certainly not be an issue mid-river, might be dodgy if you really hug the bank on the Portuguese side but can't remember the clearance. I forgot once and did a sharp right turn on hearing shrieks above my head. Plenty of space, just instinctive response on my part. :D

My notes say that forecast tide height was 1m on on trip and 0.5m on the other.

I think the height is shown 18m on some charts and I was told 23m by someone. I seem to remember that the clearance there is quoted at mean sea-level and therefore passage at LW gives greater clearance (plus suspicion that it isn't correct in the first place :D).

A friend went through in 2013 with older model of my boat and said I'd be OK.

I measured our air draft very carefully before going under the bridge:
Antenna 0.9m​
Mast 17m​
Mast base-Water 1.9m​

Total height 19.8m Manufacturer quotes 19.25m (this may be without a VHF antenna).

I didn't know the tide height when he went through but decided it should be OK as it was a pretty low tide when I was going up river. However, I also put about 60- 80kg water on end of the boom and swung it out as we arrived at the bridge. We got through easily and I so just sailed through upright on the return trip (it did look very close that time even though the tide height was less).

So it must be over 20m, not certain it would be as much as 22-23m but can guarantee 19.8m at low water on dates I made the trip. I think that the tide height was forecast to be 1m for the trip up river and 0.5 m on the return leg (based on Ayamonte). However, I'll need to check the dates to make certain.

It looked as if there were a couple of huge nuts sticking down under the bridge, so I kept clear of these. I hope this helps.

Just spotted GHA's link and realised that was where I posted the above. I obviously posted it from my own notes.
 
Last edited:
Graham376 said:
If you're playing it safe, remember low water at the bridge is 2 hours before slack. This boat didn't make it
View attachment 117675
Click to expand...
I think the owner was being a bit optimistic. I think it happened in 2013 and was a Gulfstar 60 Mk2 LOA 18.44m. I don't know the exact mast height on that model but it will be a lot more than my 42DS.:D A quick look at some drawings would indicate it is around 23.5m to the masthead. VHF antenna etc. would probably make it 24.5m
 
Last edited:
When you ride the zip wire you can see that you are well above any yacht mast that could pass under the bridge. Any such yacht might have grounding problems on the Portuguese side of the zip wire crossing. There's a sand bank.
 
RAI said:
When you ride the zip wire you can see that you are well above any yacht mast that could pass under the bridge. Any such yacht might have grounding problems on the Portuguese side of the zip wire crossing. There's a sand bank.
Click to expand...
Been there, done it, Zip wire and the sandbank. :D ;)
 
Graham376 said:
2013 could be about right, photo was taken by a friend (Nigel) who's been in Carribean a good few years now.
Click to expand...
We were in the Guadiana for 5-6 weeks (it's a glue-pot) in 2014 and think we heard about it then. Could have been early 2014, certainly pre-July but most likely to be 2013. We really enjoyed our stay.
 
geem said:
Haha, the 'power line' is a zip wire! The planning consent for the zip wire was that it shouldn't have an air draft less than the bridge. If you can make it under the bridge you can make it under the zip wire.
We have been under the bridge with 21m air draft. Can't remember the state of tide
Click to expand...
I assume a very low tide? I'm looking to go there with just under 22m. I'd be very interested to rack your brains with any memories of your calculations?
 
RAI said:
A friend measured the bridge at 23 m low tide.
Alcoutim to Pomarao would be a stretch, San Lucar to Alcoutim has a time travel international zip wire.
Click to expand...
I don't suppose you know how he measured it? I'd like to go up river but have just under 22m of air draft to get through.
 
You could do what I did on my first trip. I hung about 3x20 litres (~60kg) water containers on the end of the boom. They just touched the cockpit table and I had a line rigged from the end to the bow. It was just a matter of sliding the containers outboard and pulling on the preventer to adjust the boom well outboard. The boom was supported by a topping lift, not the gas strut. We got a decent amount of heel and plenty of clearance with my 19.8m air draft. I didn't bother on other trips when tide height was forecast to be 0.5-1.0m.

I'd probably go through with the boat heeled if my air draft was 22m, just to play safe.
 
You must log in or register to reply here.

Share this page

Top