Message 1 of 24

I made a water level to mark the waterline. Attach a 2-foot section of
clear tubing to the end of a garden hose and secure the other end of the
hose to a stationary point a few feet above the waterline. With the bulk of
the hose hanging below the proposed waterline, hold the clear section of
tubing up so that it intersects the waterline. Fill the hose with water
until the water is visible inside the tube at the level you wish to paint
the stripe. The water level in the tube will remain constant as you work
your way around the hull, so just mark and connect the dots to determine
your new waterline. Works great, assuming the boat is level and the water
isn't freezing...
Joe Kidd M15 #207 "Poco A Poco"

Message 2 of 24

All methods of putting a level waterline on a boat when it's sitting on a
trailer on land presuppose that the boat has somehow been leveled exactly as it
will sit when it's in the water. This would be essentially impossible, as I see
it.
--
Steve McClellan~~M15~#152~~Chicago

Message 3 of 24

Well, "hula pie" is hanging from the rafters in my shop [with extra
supports under the keel] and she ain't going back in the water until
that new bottom is on, so I'm glad to hear the various ideas on marking
the waterline. The supports under the keel are exactly level and yet
the old waterline was about one inch higher on the bow- should it be
exactly level all the way around? Something I never noticed until
stripping the old bottom-what a horrible job that is! -that the
waterline port and starboard are about 2 inches different and not even
on the same strake! I am thinking of adding a boot stripe- do they look
good on a lapstrake boat? What type of paint should I use for the
stripe?
While she's up I will be removing the iron board for sandblasting, etc
and repairing the area around the stop pin where a previous repair needs
some more work. How heavy are the old iron c-boards and how many people
are needed to safely remove it without getting crushed toes? Any clever
ideas on how to paint up inside the trunk?
Thanks for the great ideas and info,
Ron Goodspeed M17 "hula pie" #025

Message 4 of 24

Ron,
The paint used for the boot top is a function of what it's purpose is
supposed to be.
For boats in salt water, the paint manufacturers make boot top paint that
is anti fouling.
If you operate predominantly in fresh water, you can use almost anything.
If you have your boat hanging from the rafters, and have clear access all
around the boat, find an old skate board. Erect a vertical post on the
skateboard, and then clamp a pencil to the upright, such that you can
move the skate board around your shop floor and mark the water line with
the pencil.
I used that method with a Bolger NYMPH dinghy I built, and it worked
great.
Connie

Message 5 of 24

Connie,
It's been a loooong time since I've had a skateboard but I do have a
shop-vac on casters,so I'll give that a try. Thanks for the great idea.
Ron Goodspeed

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Message 9 of 24

Hello Wayne, Yes, I am assuming that the bottom of the keel is parallel
to the DWL- Maybe the cockpit seat should be used to level the boat, I
don't know what conventions marine architects use but many drawings of
boats in general show the horizontals of keel and seat to be parallel to
the DWL. Maybe Jerry or Bob have some better info on this? If not I'll
just figure something out- besides, You can't see it from the cockpit
anyway and with a new bottom I'll be going by so fast........ : -) .
Ron Goodspeed

Message 10 of 24

Here's an easy way to remember what Connie and I have been trying to
describe. "Did you hear about the fellow who bought water skis and spent
the rest of his life in frustration looking for a lake that sloped?"
Water in a stable enclosed area (lakes, basins, bowls, glasses, water
hoses, etc.) will always remain level. Displace that water with a rock
(which sinks) or a boat (which floats) and the water will still remain
level. If the water is contained in a lake, the waterline on the boat will
be obvious. Even if the water is contained in a hose, the same principle
applies and the water level will still remain constant.
Joe Kidd M15 #207 "Poco A Poco"
>
> Even though I don't understand this, I'm archiving it in hopes I have an
eppifany.

Message 11 of 24

Unfortunately there is no substitute for floating the boat loaded as
expected ( skipper-motor-anchor-etc) inorder to measure the waterline. A
small float or dinghy can be used with the boat in it's slip to mark the
top of the boot stripe location which should be so placed to have the
bottom paint slightly above water as this greatly reduces weed and slime
growth.
Dick, ex M23, present NS26
ron and cathryn goodspeed wrote:
> Hello Wayne, Yes, I am assuming that the bottom of the keel is
> parallel to the DWL- Maybe the cockpit seat should be used to level
> the boat, I don't know what conventions marine architects use but many
> drawings of boats in general show the horizontals of keel and seat to
> be parallel to the DWL. Maybe Jerry or Bob have some better info on
> this? If not I'll just figure something out- besides, You can't see
> it from the cockpit anyway and with a new bottom I'll be going by so
> fast........ : -) .
>
> Ron Goodspeed
>
>
> _______________________________________________
> http://mailman.xmission.com/cgi-bin/mailman/listinfo/montgomery_boats
>

Message 12 of 24

Group,
I have been following the string regarding marking the waterline, and have a
few things to add.
I use lasers in construction on an almost daily basis, and I believe that the
laser idea is a great one provided that, as Connie says, that the laser and
the entire desired waterline (both sides) of the boat are on the same plane.
I have several lasers: a 'Robolaser', a more sophisticated 'David White'
rotating laser, and a simple torpedo level with integrated laser. The former
two are self leveling--which is to say that the laser mechanism inside the
case is a pendulum, and will always cast a line/dot that is on a level plane.
The latter has to be leveled via two vials.
Any of these, when mounted on my height adjustable tripod, is capable of a
moving dot or line (manual in the case of the torpedo laser) that will give
you a virtual slice through a plane. The trick is to get the boat's desired
waterline on the same plane as the laser.
Might I suggest the following method for waterline marking?
My boat (was still 'new' when I picked it up) had three grease pencil
markings on the hull--one on either side aft, and one at the bow. When I
first launched, these marks lined up more or less perfectly with the actual
waterline.
I would propose that you load the boat/distribute your anticipated gear,
engine, etc. (perhaps humans too), and then with a grease pencil, mark the
actual waterline with three marks per side from the dock (transom/hull
intersection, amidships below shrouds, and bow).
These marks will provide you the means of confirming that the laser is in
fact on the same plane (fore to aft, and port to starboard). If the laser is
leveled, but the boat is not, or if the waterline is not too be level on
account of the way the boat sits in the water do to loading, etc., the
adjustment can be made by raising or lowering the tongue, and/or by jacking
one side of the trailer. You may have to raise or lower the level's
elevation as the adjustments are made, but it would be best to keep it level
in all directions (consistent level plane) and adjust the boat accordingly.
You know that you have it right when the laser dot or line exactly hits all
of the marks on the hull (both sides). Eventually, you will need to move the
laser to the opposite side of the hull for marking the actual line, but while
confirming/adjusting the boat relative to the laser plane, try setting up the
laser so that the dot/line plane is just below the hull. You can then use a
tape measure (held plumb from the marks on the hull down to the laser
dot/line) to verify all six marks without having to move the laser and
recalibrate.
When you do move the laser from side to side, make three or more reference
marks on opposing walls (or some stationary object other than the boat) to
use for recalibrating your laser plane.
This may sound complicated, but in fact is very easy (especially with the
Stabila level tripod that allows for vertical changes in the laser plane
without affecting level). Many of the less expensive lasers out there will fi
t a standard photo tripod. I know the laser, when set up properly, will work
with rounded objects. We have used one to set up mounts for a huge above
ground water tank.
Good luck!
Scott Grometer, M15 #478 'bebe'

Message 13 of 24

Ron,
Take pictures as you progress.
Stan

Message 14 of 24

Stan, I wish I could but we don't have a digital camera- I'll ask if
any of my friends have a scanner. This "marking the line" discussion
has lots of ideas but I think the skateboard was the simplest. With a
helper a water level kit hooked to a length of garden hose is very
accurate and they are available at any hardware store- I used one to
layout the shingle courses on my house and it has a combination of 21
inside or outside corners to matchup, came out perfect. The key,of
course, is to get the boat level all the way around. I plan to use the
old marks at the stem and transom, get them level fore and aft then
level the boat port and starboard. I'll be using the water level for
this part then try out the skateboard, or shopvac with casters to scribe
the line which can be confirmed by the water level except aft where the
DWL will have to be marked on a nearly horizontal surface. Wooden Boat
#167, August 2002 has a good article on using a laser level for taking
off the lines of historic boats.
Ron Goodspeed
M17 "hula pie" #025

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Message 16 of 24

> This paragraph begs the question, "How do Jerry and Bob mark the waterl=
ine for
> new boats offered with boot stripes?" I have been only half paying att=
ention to this
> exchange because my boat has a factory boot stripe and I figure it's =
an infallible guide
> for bottom paint and new boot stripe paint, so how do the professionals
> do it, especially in a mold?
>
Hmmm. I can think of one way you could mark a waterline in a mold....
Assuming the mold is in two halves you could calk the seam, fill it up =
to the
proper level with water, and then mark it.
Somehow, though, I kind of doubt that's how it's done. :-) Perhaps Bob =
or
Jerry will enlighten us.
Tod

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