Air Draft - who cares?

dunedin

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I was very much thinking in terms of yachts with masts. None of which are going under that....

I guess I'm struggling to think of a bridge that different 35 foot cruisers (for example) would or would not fit under... Most are either very comfortable or just not an option.
As noted earlier, very common perhaps for OP based in Norway, and also around Sweden, Denmark etc.
A few bridges and also power cables around W Scotland with heights between 12m and 20m which can limit entry to some sea lochs or inner anchorages. The Falls of Lora bridge is one example that many yachts can get under, but we can’t. Scalpay Bridge we avoid at HWS, but otherwise OK.
But agree, not a huge priority for most boat test readers
 

Motor_Sailor

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Especially at Cape May in Delaware. The bridge is 10ft lower than all the others. I knew we had clearance, but boy did it look scary!
 

jdc

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I was very much thinking in terms of yachts with masts. None of which are going under that....

I guess I'm struggling to think of a bridge that different 35 foot cruisers (for example) would or would not fit under... Most are either very comfortable or just not an option.
Power cables are just as important, and the power line just downstream of Weir Quay could be an issue for some 35' boats and not others.
 

Sandy

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I've wrtten to YM a few times suggesting that they include 'air draft' in the statistics for the boats tested, to be told that it can vary.
However a builder should be able to state the air draft of any boat he builds otherwise how do owners know which bridges are safe to pass under? or what the clearance is?
With the proliferation of bridges these days I think it just as important as draft - any thoughts?
No reason for the manufacturer not to state what the air draft is on a production boat. YM were covering their backsides by avoiding the question. A simple statement saying that the given air draft is to the top of the mast would suffice. I would hope that, being practical people, we could then make any adjustment for antenna, crew and beer. ;)
 
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James_Calvert

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In Dutch waters it is more than handy to know your air draft. I have been asked my air draft so they did not lift the bridge deck more than strictly necessary.....

I think the lifting Kingsferry bridge on the Swale off the Medway used to ask the air draft too.
 

BobnLesley

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Years ago we took a Vega up the river to Agde in the S of France. The pilot book and calcs said I would only have about 5-10cm clearance, but the top 80cm was VHF antenna and that was in need of changing anyway. In the final 20m of the approach, already lined up for the channel I just couldn't look any longer so turned my eyes away to see the flotilla of local mobis, day-boats and trailer sailers that were astern of us scattering in all directions; they clearly thought it was going to get messy. Safely through going up and scraped - it still worked - the antenna exiting at a higher state of tide and we'll worth visiting
 

Momac

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There are plenty of low bridges locally to us and not many yachts.
But as said you do have to factor in extras like antennas
The clearance under an arch is at its centre. The water level varies .
Passing under the lowest bridge for me I have to lay on the flybridge helm seat .
The video is not me but a very similar boat
 

Mudisox

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Classic RYA theory test is up the Penze River to the South of Roscoff. 16m at High Astromical Tide, and needs a clever calculation near Low water to have enough depth under you.
However once through [and much helped by landing a crew member to view for clearance there is a delightful river, Nature reserve and town which is so small that it is looking for a horse to be a one horse town. You do have to dry out though, against the Quay.
 

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