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NLOM1

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Hi

Please excuse this very naive question.

If the keel mounted maststep is level when using a spirit level can I use this as a base to ensure other level objects i.e. bunks, chart table are indeed level?

In other words, in theory, assuming that the ballast is correct and the water totally flat will the mast step be parallel to the water?


Many thanks
 
In theory yes - very few mast steps are level to the waterline though, so I would be dubious whether yours is.

I have been through this as when fitting out Roach I had no idea how to get the bunks level with the waterline. In the end I gave up and asked a boat builder to work it out for me. The level he arrived at was alarmingly steep. There is certainly an optical illusion that happens on land. From then on I marked my good spirit level with tape and worked to that ever since. Roach was on land at the time - and few yards lay a yacht to her waterline on land.

Seeing as you are afloat - I can't see why you need to reference the mast step. Surely the spirit level will tell you all you need to know?
 
Hi

Thanks for your response.

She is on land set up on ubiquitous oil drums which I am about to replace with proper supports. I want to ensure that I have the boat balanced correctly. Also I am in the process of replacing the main beam. During this process the coach roof has dropped slightly on one side. I want to ensure that I have jacked it up level. Is there anywhere on the boat that I can work to...?
 
Sorry - I assumed wrong that you are on water.

What about existing furniture? Is she empty or something?
The chart table, galley or a bunk must be a good start?

Don't rely on the cabin sole. Ofcourse you can check your heel with a spirit level. As for your fore and aft trim that might be harder if you have nothing to reference. My boatbuilder referenced the copper fastening near the waterline - but then Roach was stripped of paint at the time. You could still measure down from the gunwhales to the waterline and transfer to the inside if there is no furniture?
 
Hi

No, everything is stripped out and I reckon the gunwhales rise slightly to the bow. The cockpit locker lids/seats are still in place, I could compare those to the heel... hopefully they will prove each other 'right'. Thanks for your help.
 
have you had the boat afloat? Did she float level to the painted waterline? If so set up a long level parrallel to the waterline amidships and mark the position of the bubble. You can the transfer this inside either for each surfice or to set up a string to measure from. If you can do it this way sometime you can find a scribed line that the builder put in to where they expected the waterline to be. Internal surfices would have been parallel to this.
 
My East Anglian plans show that the cockpit seats are level with the waterline. Not surprisingly I suppose as if they were sloping forward everyone (all four of us) would be sliding down together and bunching up on the cabin doors!

It may well be that yours are level as well. If so then make up a spirit level with a correction built in, or jack up the boat until level.

Athwartships is not a problem of course.
 
If you're alterations are going to change the boat's trim, the original waterline may not be correct, especially if you are changing the engine (if fitted). I just repainted a boat and scraping the antifoul off showed it had had three different waterlines during it's life. I re-floated it to determine my own.

Once you have the waterline and have it chocked up to match that everything should fall into place.
 
Not sure what type of boat, but traditionally on a classics anyway, the waterline has a healthy boot topping above it that sweeps up to the bow and up again at the stern in long gentle curve. This is much more easthetic IMO and also more forgiving should the trim change (ofcourse you should be trimmed level using lead pigs).
 
I have gone though the same situation with my refit.
The way I did it was to use one of the cheep laser levels with a tripod borrowed from a friend.
Mark with chalk the water line fore and aft it should be scribed into the hull if it's wood as Phil has said check if there is more than one water line and it should be marked at the top and bottom usually about 2 to 3 ins apart another thing is she will look right when you stand well back.
Take extra care to set up the level about 25 ft away on it's tripod at near the same hight use a measuring stick to allow for the actual difference off the water line NOT the ground and the jobs an easy one.
Just a good straight piece across the beam to set her up with a spirit level athwart ships.
Then solid chocking is the order of the day make sure you chock fore and aft if you have long overhangs.
You will be surprised how much you will pursue the job to set her up level and true it gets you quite enthusiastic to achieve perfection.
I hope this helps.
Cheers David.
 
There is very little that you can be sure of in an old boat. Basically you have to begin with the scribed waterline, which should be at the junction of the antifouling and the boot topping. This should have been put in buy the builder to indicate the designer's intended waterline. This should be level fore-an'-aft and athwartships. Fill a garden hose with water and check that the waterline at the stem and sternpost are at the same level. Then check from side to side. If there is a mark of the immersion around the waterline you may find that it is out of level. This is something that must be corrected with ballast when afloat. Once you have the designed waterline level you can the use a spirit level to find out what else is level. Hang a plumb-bob from the centre of the companionway hatch and see if it touches the middle of the cabin sole, or the line of keel bolts. I found that my old ketch has 5" more belly on one side than the other, so I could never get her level, no matter how much I tried. She was built by eye, you see.
Peter.
 
Sounds like you are refitting bunks etc so quite a project. I've done this myself, why not start from the premise that, as originally built, the bunks were level when afloat and work to the same lines? There must be some evidence of this left if you are refitting. Alternatively, find the scribed water-lines if present, level her to this with a laser level, and transfer reference points to inside. Another usful piece of evidence is the galley sink, because the sink has to drain. Either way, find the previous evidence, reference to this and level the boat to the reference. Like the man says, hire a laser level to transfer level datums inside/outside. When you refloat her, ballast to trim her correctly. The main thing is, get the bunks level because, believe me, if your head is higher than your feet you'll never sleep comfortably aboard.
 
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