Waterline Location

[Moose]

I tried to search the site but no luck.

Would anyone with a DSIII be willing to measure (or share if you know) the waterline location of the boat? Seems like the best way to do this would be to measure from under the gunwale/deck-hull joint down to the waterline at the bow, stern, and a few spots in-between.

I believe I have an '82 O'day DSIII.

Thanks for any help in advance!

Edit: Not sure why I thought I might have a spindrift boat. Sorry for any confusion.

[Bob Damon]

Spindrift did not make the DSIII. You have a Spindrift DSI so the waterline will be the same as any DSI. Good Luck!

[Moose]

Spindrift did not make the DSIII. You have a Spindrift DSI so the waterline will be the same as any DSI. Good Luck!

I'm not sure why I threw spindrift in my post (Brain fart). As the boat has large O'day decals on the side. I am sure this is a DS3.

Thank you for helping clear that up.

[GreenLake]

I tried to search the site but no luck.

Would anyone be willing to measure (or share if you know) the waterline location of the boat? Seems like the best way to do this would be to measure from under the gunwale/deck-hull joint down to the waterline at the bow, stern, and a few spots in-between.

You need only two points front and back and a laser level. (Make sure the boat is level from side to side...) If you don't run to a laser level, a bit of transparent hose filled with water will allow you to mark your boat, but then it has to be physically level so that the two measured points are at the same height).

On my DS1 the waterline comes up about 1" at the transom (the rest folds under). In the front, the top edge seems to be just at the point where the rather straight bow turns into a curve. (There should be enough photos of DS boats on trailers for you to verify this.)

In Drawing 8.2 in the handbook, the waterline seems drawn a tad too high, I'd say it's the location of the lower of the two lines is where the top edge of mine sits - relative to the shape of the bow, not the distance from the rubrail, which I don't know whether that's to scale.

Here's someone's photo for comparison:

If you've equipped your DS with something heavy and permanent, like a battery, you may want to depart from the factory location to move the stripe to where the boat does sit in the water.

PS: as this is not about the DSIII, I've moved the thread.

[jdoorly]

Sorry to add confusion, but there are several waterlines. The first is the actual place where water and air meet along the hull. Most boats do not paint the water line at that point because it makes the boat look like it is sinking. Painted water lines are normally an inch or two or three above the actual waterline. If I were O'day I would paint the waterline at the place where the displacement was about 1050 pounds so the boat was 'on it's lines' with 3 crew. But I'm not O'day and I don't know. Perhaps the class measurer can clarify this.

[GreenLake]

I don't know why O'Day decided to place the waterline where it is. Many boats, particularly smaller ones, live happily without any waterline. It's a nice decorative touch for the DS, but it's also useful if you keep your boat in the water - as there'll be a different kind of "waterline" forming all by itself. I always suspected that dark waterlines on light hulls had the secondary purpose of hiding that "scum line".

If so, that would affect placement.

What I reported, is simply the factory location. On photos of my boat I can see that in the front half of the boat, a bit of waterline gets exposed in the troughs of the bow wave. In the rear, the factory waterline is "under" the boat - the two sides come together and are about 18" where they meet the transom. The top edge of the connecting line cuts across the lowest 1" of the transom, and the bottom edge is actually under the hull at that point.

Now, with any crew, the DS sits deeper in the water than that in the rear, unless the crew are sitting very far forward. It still doesn't look like the boat is sinking. (At least, looking at those photos, I never got that impression). What would look odd is if the waterline was placed high out of the water and were seen to be at an angle.

To add to the confusion, once the boat is moving out on the water, wave action will obscure and interfere with this neat pattern, so that some part of the waterline may be exposed that isn't visible for a crewed boat at rest. Other parts are obscured by the bow wave or passing waves.

[jdoorly]

HI Greenlake, The scum line should be an exellent indicator of the waterline but in thinking about it the question is raised about where scum actually attaches to the hull. I would think that wave action, etc, washes scum onto the hull where it dries but the continuing action of the water, in flat conditions, washes the scum off below the scumline. This leaves the scum only above the waterline. Is this an accurate representaion of what you see with boats kept in the water? Or, is scum both above and below the water?

I have never seen my boat floating, with no crew, at the bottom of the painted waterline. The painted water line is well submerged when sailing. The question remaining is where should the actual water/air interface strike the perimeter of the boat a) when empty, and b) when sailing?

[GreenLake]

Me, when I paint a boat (just did mine, by the way) I'm a bit of a traditionalist. I just follow what was there. I merely suggested that if someone permanently installs heavy additions, they could move the waterline to match - if they so desire.

I dry-sail my boat, but I have photos of it floating empty and with various crew. The back of the boat seems to be submerged more than indicated by the waterline - however, I could have unintended ballast - haven't removed the foam from under the seats yet - the part I can reach is dry, though...

I don't have first hand experience of access to DS boats that are on a mooring or dock. Perhaps others can chime in.

I honestly couldn't advise you on which theory for placing a waterline is "correct", as far as my boat is concerned, looking good on a trailer is part of it as well

[Moose]

Hey guys, Thanks for the advice.

I will be keeping this boat on a saltwater mooring so antifouling is a must. I agree that the waterline (WL) should be painted higher than the "factory" location on any boat that is not dry sailed. Another alternative would be boot-striping.

When I had my DSII after a season on the mooring there was a dark discoloration 2-3 inches above the WL around the boat that was nearly impossible to get off. I do plan on painting the WL on this boat 2-3 inches higher than the apparent WL. I am also considering boot-striping up to a load water line (LWL) of about disp. +400#. I found that any time that the water is not dead calm or there was rain in the cockpit it was above the WL

My principle concern with picking two spots and painting below the line they make along the hull is possibly not having this line be parallel to the water. As far as I know there is no good indicator of how the boat will level in the water ( i.e. transom is vertical, or c.b. box is horizontal) Although I think the transom might be a good indicator. I might try that! The location where the mast mounts to the deck is probably also a good indicator of how the boat will sit as the DS relies more on mast bend than rake. Lastly, it's way too cold to put the boat in the water to mark it off.

[jdoorly]

Hi Moose, As these boats age their gelcoat seems to get more porous and harder to get clean, hopefully the paint will fill the pores and be easier to clean. Wax would also help.

The DS, as well as most boats, has a painted waterline that rises from stern to bow, from 1 inch high to 2 inches high at the bow. I hope to paint this year too, but I'll probably paint 1 color from sheer to centerboard and I'm thinking of adding this graphic I made on the bows...

[GreenLake]

If you mark the two points (1" above bottom of V on transom in back and right where the straight line of the bow begins its turn in front) then you nail the position of the design water line. You can go higher on both sides, of course. If you look carefully at a lot of photos you'll see that jdoorly is correct and that many times the waterline will seem a bit high at the front. I think it's just something subtle that looks better (and certainly better than the reverse). I certainly see that for the factory waterline on photos of my DS1 (located as per above).

[jdoorly]

Sorry, my description of a 'rising waterline' was incomplete. I meant that the bottom of the painted waterline was horizontal, and the top of the paint rises from the back to the front, that the actual painted line is thicker at the bow.

[GreenLake]

Having just painted mine, I can't attest to any variations in thickness. However, the angle of the hull is different so that the projection of the waterline onto a vertical surface would be taller in the front.

The stripe itself is of constant width. (Easy to see when you try to cover it with tape).

[jdoorly]

What he said.

[jdoorly]

Here is further proof of a constant 2" thick painted waterline. Although the DS has a constant width waterline not all boats do and the perkier rising waterline is considered more attractive in the same way as the ramshorn sheer.

BTW, this pic is my careened DS. I have stopped trying to use the mast as a lever and use a come a long directly to the port chainplate. I also use the anchor rode (from chainplate, around a tree, then to the other chainplate) to hold the boat to a tree while I drive away with the trailer leaving the boat on the ground (without damage). I also modified my trailer by removing the rollers and installing a full center bunk- works nice!