Setting out a waterline

[Daydream believer]

Add some water so it's nearer the top of the tube. Equal amounts at both ends, of course.

I do have one. Had it for 50 years at least. My grandfather swore by his. I swear AT mine. If I was doing the job I would use my Carl Zeis optical level which I have had for 59 years. My father bought it for me . I also have a Hilger & Watts one. but the lens is no where near the quaility of the C Z

 

[AntarcticPilot]

Wouldn't it be easier to get a big bath of paint and float the boat in it?

 

[fisherman]

Wouldn't it be easier to get a big bath of paint and float the boat in it?

Dammit i think you just hit the nail on the thumb!

 

[Daydream believer]

Wouldn't it be easier to get a big bath of paint and float the boat in it?

Just raises questions
What antifouling paint to use. Sea jet, Flag, International Cruiser Uno Etc.?
Then if the paint has a higher specific gravity than water ( Might have) the waterline will be too low. So how many rocks do you put in the boat to compensate & get it to allow for wave action. Then how do you keep it level whilst you lob them in
Do you leave the anchor on board & how much rode should you store whilst doing it

 

[fisherman]

Just raises questions
What antifouling paint to use. Sea jet, Flag, International Cruiser Uno Etc.?
Then if the paint has a higher specific gravity than water ( Might have) the waterline will be too low. So how many rocks do you put in the boat to compensate & get it to allow for wave action. Then how do you keep it level whilst you lob them in

Don't be daft. just add water from a hose. You need to know the sp gr of the paint and displacement of the boat...no worries.

 

[Hacker]

We teach our students 5 ways.
1. String method as shown by @fisherman . Ideally boat level but you can adjust the wooden bearers to take account of any “off level”.
2. Use a laser. Needs enough space either side. Ideally level boat but some lasers can be set to an inclination.
3. Use a water level.
4. Chuck it in the water and mark the actual waterline.
5. Hope the original waterline is visible!

 

[burgundyben]

Boat still has to be level both ways, I just realised.

And that can be the tricky bit.

 

[Daydream believer]

Don't be daft. just add water from a hose. You need to know the sp gr of the paint and displacement of the boat...no worries.

What if the water all runs to one end? & it goes , say, bows down. How do you know that it will float level as it fills?