A practical waterline.

[HarryH]

I'm getting ready to mark the waterline on my 24' lobster/picnic boat and am wondering if I should as a practical matter, paint it a bit above the designed LWL (toward the sheer), to allow for scum, loading, and appearance etc. Any convention, or experience backed suggestions for this?

The boat is designed to displace 3300 lbs. I am not going to use a boot top. I realize that the WL may need to shift a bit once afloat and in use, but I've got to start somewhere, so I can turn this hull over!

Thanks..

_H

[mmd]

An inch above LWL is common, and I usually have the waterline arc slightly upwards at the bow as I think it looks better and allows for a bit of trim without looking too obvious.

[HarryH]

Just what I was looking for Michael, a bit of what is "common"...

Thanks for the tip on swinging the bow end of the WL up some, too. I know that is often done on boot tops, but if I do not plan on one, treating the WL in this way makes sense.

[Tonyr]

Harry - what's the background of the design? Did you design the whole thing, or just part?

Regards, Tony

[Candyfloss]

What Michael said, but I'd go a bit more than one inch.

[MiddleAgesMan]

A boot stripe extends 2-3 inches above the dwl on the typical small craft, more or less depending on the size of the boat and, more importantly, the height of the topsides.

If you're omitting the boot stripe you should bring your bottom paint up to whatever level (the upper limit) you would have painted the boot stripe. It will look better and will give you some leeway if the boat is overloaded or out of trim.

[mmd]

The LWL should be located at the draft of the vessel under ordinary load (people, portable equipment and consumables), so it should show a bit more when hanging on its mooring. The TPI of Harry's boat will be around 600-700 lbs, so I think that an inch of bottom paint above the LWL will be adequate to absorb any normal extra loading without submerging the top of the paint line. Of course, the submersion will be greater at the bow if the load is not balanced over the LCB, hence my suggestion to arc the LWL up a bit at the bow.

[HarryH]

Harry - what's the background of the design? Did you design the whole thing, or just part?

Regards, Tony

Tony, the design is of the late Frederick Bates of Damariscotta, ME and is circa 1969. I will make minor mods. To my knowledge, plans are no longer available from his estate or elsewhere, which is really too bad. It's a sweet boat, unique for its size and lines; it is a scaled down version of the downeast boat with soft chine, beautiful sheer, tumblehome, etc.

Here's photo progress on Picassa Web (I am a bit further along):
http://picasaweb.google.com/Harrible/PogoConstruction#

[rbgarr]

The Pogos I see around here tend to ride bow down a bit, so you may want to consider a swept-up (toward the bow) look to your waterline. The forefoot on the boat and raked stem are shallower than most lobsterboat hulls:

Pogo
http://i45.tinypic.com/2hi7zvm.jpg


(Not a Pogo, but a similar trim appearance when idling.)
http://i48.tinypic.com/2mcunms.jpg

Best of luck with your project!

[mmd]

rbgarr, I have a closely held and utterly unjustifiable opinion on why a lot of the "lobsteryacht" hulls ride bow-down: I believe that when designer/builders of these boats get the bright idea to use a lobsterboat hull as the basis for a pleasureboat, they fail to take into consideration how much "stuff" people actually put aboard their boats. The new lobsteryacht looks fine when delivered, but as soon as Mona & Earl get their new boat, Mona starts to make it "homey". Spare blankets, books, stereo, warm clothes, rain clothes, play clothes, canned goods, anchors, etc., etc.; and it all goes in the lockers way forward. The hull has a fine entry (one of the things that makes these hull forms great, BTW) and therefore little reserve buoyancy, so the three hundred pounds of "stuff" placed way forward puts the boat out of trim. If you design the boat to have a little bit more underwater volume at the forward stations, or merely convince the owners to throw away half of this uneccessary junk and redistribute the rest, most of these type of boats will trim just fine, thank you.

That's my story, and I'm sticking to it...

[rbgarr]

mmd,

You'lll get no argument from me!

My experience with the lobsterboat type comes from the other side of town, so to speak. An awful lot of smelly detritus gets thrown up into the bow of the working boats: broken lengths of pot warp, ripped gloves, shredded aprons, rotten bait bags, empty cans of motor oil or hydraulic fluid, grody five gallon buckets full of who-knows-what, etc.

Altogether it doesn't weigh much but it sure keeps anyone from spending much time up there, so the bow never gets weighted down to speak of. :D

Not so aboard the yacht versions, as you say.