Waterline Marking

[Temeraire]

Firstly, Hello to all. Does anyone know how, or have any ideas on how to mark up a waterline for antifouling on a new hull, with no line currently marked, and which we have not seen in the water yet.

Short of just guessing where It'll be, I have no Idea. With expense of the new boat we could do without launching to see where she lies only to pay again to lift her out & antifouling. any suggestions or advice?

Any assistance gratefully received,

Matt.

NNNN

 

[Guest]

If you know the "stated" draft of the vessel.....measure up from the lowest point of the keel, or prop or outdrive to that point on the hull, depending on what kind of boat it is, then add a couple of inches just to be safe and paint your bootstripe there and bring the anti-fouling point up to the bootstripe. Hope that helps.

Reality is the cause of all stress!!

 

[spark]

Morgan has the right idea but make sure the boat is level both athwartships and fore-and-aft. Best way to check the latter is to put a spirit level on the cabin sole, which should have been built to be level with the waterline.

 

[spark]

Should have added...

... to mark the waterline you'll either have to set the boat up on a level floor and then use a light stick that is the same length as the maximum draft to mark off the wateline on the hull. Hold the stick lightly at the top between thumb and forefinger to ensure it hangs plumb to the floor. If you can't put the boat on a level floor or smooth hard-standing you'll hve to set up a datum of transverse battens fore and aft (and probably midships) and use a longitudinal batten to measure up from.

This all takes a while to set up and I have recently seen a laser level thingy which looks as if it will shine a nice level red line onto your hull from the simple datum of a tripod. Axminster Tools (www.axminster.co.uk) are doing one for £50. If you decide to try this I'd be interested to hear the results. Needless to say, if it doesn't work I absovle myself of all responsibility....

 

[SimonD]

Re: Should have added...

PBO or YM did an article on this some years ago. Can't remember the details but it was something like set up a straight and level edge at the correct height and then use the car headlights to cast a shadow on the boat. Might be worth playing around with.

Otherwise, B&Q also sell laser levelling thingies and a much cheaper tape measure with a built in laser to project a straight line.

 

[dickh]

Re: Should have added...

Once set up, the other way to get a horizontal line is to use a hose pipe with a clear portion of hose at each end, fill with water, fix/tape one end with the water at the correct level, then walk round the boat with the other endmarking the hull with the other water level at the other end. Then join up the marks using a lath and mark a continous line, will probably need 2 people to hold the lath while the third makes the line.

dickh
I'd rather be sailing...

 

[brianrunyard]

Having got the hull level and measuring up to find the correct position. Rather than measuring from the ground in more than one place, the ground won't be level enough, use a hose pipe as a spirit level.
1. Use a hose pipe with clear tubing attached at both ends.
2. Mark a black line half way down the clear ends
3. Fill with water upto the black lines.
4. Tape one end to the hull so that the black line corresponds to the required water line.
5. Now go around the hull raise and lower the free end so that the water level is at the black line and mark the hull.

Brian
http://homepage.ntlworld.com/brunyard

 

[petery]

I had the same problem on a boat that had been out of the water for a couple of years and had been epoxied.

I was able to measure a similar boat to give me the rough line and applied antifoul almost to that line. Once it had been in the water and I had the scum line, I put a 3 inch boot topping on the hull that corrected the small errors the next time I hauled out. I would have loved to have tried the laser gadget to get it perfectly straight over the chines.

 

[spark]

Hosepipe method

I have used the hosepipe level when setting out foundations for buildings. Have never considered it for waterlines but my workshop floor is sufficiently smooth and level which makes the stick method easy. Also, I mainly work on clinker boats where the waterline tapers in underneath each land, which would be difficult to get accurate with the hosepipe. I can see it working nicely on a smooth hull, though.

 

[Temeraire]

Thanks everyone for the replies. Yes I can see what your getting at & all is becoming clearer. Hopefully we'll be able to get her set up level, & the rest should be relatively straightforward, - famous last words.

I'm going to err on the side of caution this first time, & the boot top probably won't be quite high enough, especially once the wife has loaded all of her general paraphenalia, but it should give us some protection for a year or two.

I've seen the laser levels you suggest during my pre-boat owning days of endless DIY, & usually spent a few minutes thinking of a use for it, so I can add it to my toy collection. Perfect. I'll have to keep this forum a secret from the wife if its going to recommend buying more tools. She wont like that, Suggestions to buy a new couch, curtains or re-paint the hall/stairs/landing after 6 months since last time will probably be quite agreeable though. But I'm not bitter, well not now I've got my boat.

Anyway, thanks for the advice all, it sounds simple now, but I just couldn't think what to do before.

Just one more thing, Any recommendations good or bad on makes of antifouling. I suspect its a case of you get what you pay for. We'll be marina based in the N.West & just generally cruising, farily local untill we as a crew have more experience.

I'm thinki8ng along the lines of something that won't break the bank now, but will work, & be available later on, or is just so general that we shouldn't have too many compatability problems in the future.

 

[philip_stevens]

The following was posted (today) on the WOA newsgroup - I won't reveal the poster.

"Last April I gave my Berwick 1 coat of 'Flag' antifoul paint.
When I lifted out last week there wasn't a barnacle in site nor even any
weed - just some slime.
as Flag is the cheapest AF on the market (under £40 for 2.5 L delivered to
your home), I can recommend it - from C W Wantage of Burnham on Crouch Tel
01621 785173 ( I have no association with them )."

It is copper based.

I have used XM HS300 to good effect this summer. There have been bad reports concerning the XM 2000 but I have found the 3000 to be ok.

regards,
Philip

 

[dickh]

I also use Flag Antifouling and find it OK for the price; I usually give a mid season light scrub but didn't manage it this year so I will be interested in its condition when it comes out in a couple of weeks.

dickh
I'd rather be sailing...

 

[andyball]

The laser level works ok : We had a brand new boat that had been in the water for a bit :nice easy to see tide mark : asked the yard to haul it out & mark the line before washing it : needless to say they bloody well didn't & guessed a waterline level marked with laser level.

Nice even line, but 1" below water level (grrrrrrr!). Still negotiating reduction in bill for unsightly looking job. (and paint flaking off,and scratches from slings)

 

[oldsaltoz]

G'day Matt,
Welcome to the forum, no doubt you have read the responses to date.

But no one has talked about using a builders level, you only need to level the boat across the beam, fore and aft not required.
Set the level up so you san see both ends (About 10 to 12 metres is fine) get a stick of timber about 300 mm long with a square end, tape a small spirit level to the side.

Now place the top of the tick at the point you require the line on the bow and make a mark on the stick as seen through the cross hairs on the level.
Now take the stick to the stern and adjust the tilt on the level to align the first mark, check this with the bow line and adjust further. After a couple of adjustments both will line up, now you can put the stick at any point along the side of the boat for a perfect line; marks about 100 mm apart are fine. When doing the stern marks will be much closer.

The above will give you a perfect line and save you having to level the boat for and aft, there is no guess work and no bubbles running up and down tubes, or vehicles with flat batteries from leaving head lights on etc.

Having used most of the methods mentioned above I can assure you this is the only way I do water lines now.

Soavagoodweekend Old Salt Oz....../forums/images/icons/cool.gif