Raising a Waterline

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alec

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I need to raise my antifoul line by about a foot.

Is there an easy way of doing this ?

I thought of using a pair of compasses making pencil marks above the old line about every six inches.

Any help would be gratefully accepted.
 
If you empty some extra weight from the boat you might avoid the whole problem. /forums/images/graemlins/smirk.gif
 
Now come on you lot ! Get a grip !

I need answers !

If you had seen my lovely dull white chalky topsides covered in weed, that took close to a blowlamp to get off, you'd know what I mean.

Yes, we're talking lumpy swinging mooringsvilleland. Not your marina Savoy type moorings.

Is there anyone out there ?
 
it was shown to me by an experienced boat yard worker. Its easy.

Take a good quality tape, attach it at the bow at the desired waterline heigth, unspool enough tape to go to the stern of the boat, walking away from the boat. Hold the tape up and walk slowly towards the boat, keeping the tape always properly tensioned until it touches the hull at the correct high. Thats it. You may have to do it more then once. That way, you have a straight line.

Peter
 
An easy way is to use a water level gauge if the boat is level fore and aft, and athwartships. Fix (with tape) one end at the height you want it, in the middle of the boats side, and use the other end to give you a marking level. It will give you a level height even where the boats ends tuck under.

You can do this by yourself.

Another method whereby you need two others is to ping a chalk string along the boat - more time consuming.
 
Alec,
If your present w/line is paralel to the water I think your own solution is as easy as any other and can be done s/handed and without leveling the boat on the cradle.
Jax
 
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Its easy..................

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Won't that tend to follow the equivalent of great circle route (ie the shortest) rather than the rhum line parallel with the waterline.

A laser level could be used if modern technology appeals but like the water filled tube method the boat must be standing level
 
OK then. If you just use the compasses then in some places the measurement will be vertical but at others it will be at a slant ( eg near bow and stern flares ) so line will not be level.
Water level will work but now the laser levels make this a doddle. Set it up and swivel it from bow to stern after adjusting to height you want. Put in marks ( OHP pen would do fine) along hull then join up. Careful masking after that.
 
Absolutely. If there is tumblehome (inward slope in automotive terms) then cord will roll down further as you lay more of it on the hull.
There is a very time consuming method using level boards forward and aft and touching the line in one spot at once, but far easier with a £15 laser level. Why make things difficult?
 
If your boat's in the water, you can use your pair of compasses to mark the new level one foot above water level. You just need to launch your dinghy on a day when the water is flat.
 
Er, I tried the laser method, and I should point out that it depends on the boat itself being levelled both fore and aft and athwartships. Either that or work out a method of adjusting the plane of the laser so that is is parallel to the plane the water level should be in. Unfortunately I'm not that clever, but I did discover that a slightly wobbly waterline is almost undetectable once the boat is afloat. Which is fortunate.
 
Method 4.
Assuming the boat is ashore and level(ish)
Cut a bit of ply or card 12" by say 12" square
Hold a 4 foot spirit level at the existing water mark at 90 degrees to the boat slide the square ply along the level until the corner just touches the hull, mark this point. Repeat ever foot or so, join the dots.
 
I would have thought that as long as the boat is level athwartships (laterally) then you only need to tilt the laser mount so that your pre-marked stern and bow marks (you did pre-mark before slipping it didn't you?) line up with the laser. Once marked you can check side to side with a tape vertically down from the rubbing strake to make sure there is equal freeboard.
 
Well, however you phrase it, as long as the plane that the laser is scanned through is parallel to and at the same height as the plane that the waterline is in, then it will work. Actually, once the boat is ashore and propped up, levelling her (only a 3.5 tons displacement long keeler) is not a trivial task: even if you're prepared to pay the boatyard for their crane and half a day of their time, which I'm not, I'd still need a straight, flat surface to put a spirit level onto, which I can see while the crane is lifting and dropping her... and no, I didn't pre-mark it 'cos I didn't know I'd be doing it until the spring. It's now gone onto the "b" list of things that I'll get around to when there are less important things to do.
 
Re: Global Warming...

Each year for the past 5 years, my waterline has risen by the width of a roll of masking tape by this method. My original level was tken by the green slime line.

Cameron
 
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