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I keep the boat on the dock and after our first good rain I found that all of the water had accumulated forward and back to midship. Moving 9 gal of gas from the forward compartment all the way aft got it draining and the scuppers were still above the water line. This is with a heavy 4 stroke 40 on the transom. If it had been a light 2 stroke 25 the bow down would have been even more.
Is this a building error? I don’t think so. Even if the strong back had not been level the stringers define the sole level relative to the wetted surface. It seems like she needs a little more volume up in the bow.
I don’t like the solution of moving the gas tanks aft since standard 6 gal tanks don’t fit in the rear compartments.
Maybe building a false deck 1inch high starting at the forward bulkhead (Frame A) and tapering to 0 at midships would do it.
Any other suggestions?

How does the boat float? Is it on the waterline? If yes, then the sole is wrong. If not it is a question of weights.
The waterline is calculated for 2 men in the middle, a 25 or 40 HP (can't remember but I will check), gas in the middle, 1 battery in the stern.

I checked your pictures and the boat looks like it floats where it should be, maybe a little down by the bow but not much.
You have 2 tanks forward, is there anything else heavy there?

Hi Jim dont like to hear that about the water forward but i must admit I have been looking at mine and wondering the same thing , I put a 12 gallon gas tank between frame a and the bow I plan to put a 40 on mine as well Ive got about a month before splash down it would suck to have to put a false deck as you mentioned. Im just trailering so I guess I would live withit good luck nice looking boat

jay burgess capecod ma

First, great job on the boat. It looks great.

Didn't I read that you added a bit to the forward sheer of the boat? That would add a little bit of weight forward. Maybe just enough to bring the bow down a hair at rest???

Jacques- She seems to be on the water line but until I pull it I can't tell exactly where the forward (bow area) line is relative to the water. It does seem to extend further forward than I had projected the waterline. Tomorrow I will try to measure the distance from the most forward water mark to a line parrall to the stem.

As far a weight forward the only things are the casting deck which extends 13 inches aft of frame A, 3/8 ply with 6 oz dynel fabric. Also a 8 LB danforth anchor with 6 ft chain and 150 ft. 3/8 line. Plus of course 2 -6 gal gas tanks under and aft of Frame A.

The 8 inch addition to the shear, tapering to 0 in 6 ft can't weigh more than 10 lbs.

Best solution I have heard so far is to always keep a 98QT cooler in the back filled with beer.

JimMac wrote:Best solution I have heard so far is to always keep a 98QT cooler in the back filled with beer.

Will you run out of gas before you run out of beer?
Do you think moving the battery from the console to an aft location would take care of it?

Yes, no need to think about a modification to the sole, just move a battery towards the back and that's it.
In this case, there is some extra weight with the modified bow, not much, maybe 10 lbs, However, the heavy engine should compensate for that.
It's the two tanks and the forward casting deck that could be the culprit: nice hatch and maybe more stuff we don't see.
Is the console where we show it? At 45% of the DWL from the transom?
I can't say why that happens until I have a list of weights but it is clear that you have too much weight forward.
There is nothing weird about the hull design, it has a proper balance of volumes.
For those who are building the boat, the LCG (Longitudinal Center of Gravity) should be at 68" forward of the lower tip of the transom. Move your weights accordingly.

Consider getting a different tank size as well, as Im sure Moeller and the others make tanks that will fit in some pretty random places.

Do you have a livewell in the boat? Fixed or loose? If you must keep the gas in the bow, you might be able to just ballast with the livewell in the back.

Another little cheat, if all you are doing is trying to keep rainwater draining, is to just take one of your gas cans out of the bow when you leave. Consider it your "fill-up" can and take it with you, thus dropping the bow weight while on the dock.

Love that little boat, just have to figure out the nuances of building it for my needs and talking SWMBO into another big project.

E

It appears for other FS17 builders that putting the gas in the bow is not the thing to do. It appears that you can put a sunken compartment in the center of the boat between the stringers under the center seat for those going that way or under the console for those going with a console.

This will keep your CG more balanced and keep what is happening to JimMac from occuring to others.

Tom

Will you run out of gas before you run out of beer?

It's happened.



But who cares?

I decided I'm not going to worry so much about mine until I get it in the water. I have plenty of unused weights around the house I can throw around the boat A pack of sinkers here, a tackle box there, and a cooler over there and I should be good to go
Jim, moving the battery would probably be a good quick fix. You boat looks like it floats great with you in it. Is is only when your out of the boat that the bow is heavier?

Bow is heavy.. the problem is usually the other way around isn't it...
the cross you bear being the first one splashed... LOL

After moving the gas back How much above the water line were the scruppers?


this boat must be balanced pretty darn good if that little bit of weight moves it back and forth. especially with that big 40 on it.

nice boat.

mecreature wrote:
this boat must be balanced pretty darn good if that little bit of weight moves it back and forth. especially with that big 40 on it.

It has a small water plane and is sensitive to weight.

Ok , I just spent and hour or so measuring and shifting weights around. Here are the results.

The boat (fS17)Forward Has non standard shear 10lbs, Sole from 13 inches behind frame A and 3 inches up and goes forward to stem10- 15 lbs. Casting deck from stem back 48 inches 15lbs. Anchor and line forward of Frame A 18 lbs. Gas tanks 2 portable 6 gal under rear portion of casting deck 110 lbs
Mid ships Foam consol with controls 20 lbs Battery 39 lbs
Transom 40 hp 4 stroke Honda with electric tilt 212lbs Soles engine well and side compartments 6 lbs
Foam to sole from front to back 5gal
So there is about 75 Lbs more engine weight than a25hp 2stroke and 39 lbs battery moved from rear to amidships which lightens aft 15 lbs – net 60lbs heavy aft.
Off set by 110 lbs gas moved from amidships forward = 55 lbs effect plus sole, casting deck, shear additions of 35 lbs For a total of 90lbs heavy at bow.
In summary it is about 30lbs heavy at the bow.
Using a level with no one aboard it shows 2.5 inches slope to bow (bow down) along 11’ sole.
The water line at bow is 26â€

Jim your weights are fine but you have not taken the LGC into account. For example if you move 10lbs 1ft it weighs 10lbs, if you move it 2ft from the LGC it weighs 20lbs. Redo your numbers using Jacques 5.667' LGC from the bottom of the transom and see how you fair.

for example 60lbs x 5.667 = 340 aft 90lbs x 7' = 630 at bow effective weight on LGC is 290lbs effective weight a much bigger difference and the one that must be considered when comparing weights in a boat. This is what Jacque was referring to in his 3rd message.

This is just a simple example as you will have to mark the LGC and then measure each of the distances. Or just get a rough idea and measure your front distance to the center of the gas tanks from LGC.

Tom

As I understand it the boat was designed for the sole to be level with: a stroke (140 lbs) and Battery (39 lbs) aft for a total of 180 lbs , minmal weight forward, consol 6’ 4â€

Nope somethings funny in Denmark.

Tom

Yes, there is something wrong but what?
It can't be the hull shape: it is very close to the Simmons Sea Skiff plus, the hydrostatics were calculated with top of the line software.
Either there is a volume or weight problem or the sole isn't level.
All that is diffcult to imagine, it would have created other problems.
I'll check again on Monday but in the mean time, don't calculate moments, just move weights around.
You have a lot of weight forward, more than what you estimate.
If moving tanks to the middle or a battery to the back solve the problem. just do that.

Jacque as a summary he used a 11'(length of sole) straight edge with a level and was bow down 2.5" in current configuration.

First he moved the gas tanks(110 lbs) back to motorwell frame, now bow down 1".

Second filled cooler with 154 lbs of water placed at same frame, now transom is down 1/2"

It appears from this that 210-215 lbs at the motorwell frame is needed to bring his sole level.

Hope this helps.

Jim correct me if I'm wrong.

Tom

Tom and Jacques- Thats about it. I hope to get some sea hours on it this weekend and report back more on how she handles.

Tom, your reasoning is correct but it is abnormal to have to move so much weight back to get the boat level.
I am 300 miles away but on Monday, I will run a complete spreadsheet with the modifications and post it with the hydrostatics.
I did it for the basic version and we will compare.
I guess that we will discover that there is too much weight forward.

Didnt you move youre center consul forward

It's Monday noon and I still did not have the time to start on the spreadsheet: be patient, it may be for tomorrow.

No problem, I'm using the boat as she is.

One measurement that would help determine if the hull is riding bow down is the distance of the waterline at the bow in relationship to a plumb line dropped from the bow.
If this shows the hull to be on its marks then the only thing left is the sole not being level, which is what I suspect.

Since you modified the bow, to measure at the transom is much more accurate.
I'll try to post the spreadsheet and related drawings today.

JimMac wrote:No problem, I'm using the boat as she is.

One measurement that would help determine if the hull is riding bow down is the distance of the waterline at the bow in relationship to a plumb line dropped from the bow.
If this shows the hull to be on its marks then the only thing left is the sole not being level, which is what I suspect.

Hi Jim,

How do you suspect the sole could have ended up not level?

Steve

Spreadsheet done.
It's mostly in metric but it all adds up nicely.
The designed LCB, boat level at DWL, is at 3,378 m from my design origin which is the tip of the bow.
The boat with a small console, a 263 lbs engine on the transom, battery in the console, gas tank in the bow 12 gallons half full, a small anchor etc. in the bow locker, two men at the console (one behind, one next) puts the LCG at 3,341 meters.
That means a difference of 1-1/2" which equals to a few thousands of an inch at the waterline. Move a six pack of beer a few inches and it will be right.
The boat floats as she should be and BTW, that is clear from the pictures, she looks right.
Now, lets try the boat empty but with 12 gallons of fuel forward and some extra 50 lbs for the modified sheer and stuff.
LCG is now at 2.935 mm.
I calculated the new trim for that LCG and the bow goes down 48 mm (1-3/4") and the transom lifts up 100mm = 4". Bad.
This is close to what you measured.
Conclusion:
Your hull shape is correct, the design is correct but because of all the weight at the bow, she will not drain at the dock unless you move some stuff.
I did it once more with standard bow (no 50 lbs of raised sheer and 1/2 a tank) and she drains. Borderline but it drains.
Even then, to be safe, if I leave the boat unattended at the dock, I would keep the battery or the anchor in the stern.
For all builders who plan to leave the boat at the dock, I would move the battery to the stern.
I will zip the Excel file and upload it if somebody is interested but the good news is that the design is right and the JimMac's hull is correctly built.
It's just a matter of too much weight forward in a boat that is sensitive to it.

PS: the question of what outboard weight I use comes back often.
I use the ABYC/USCG weights, not a 2 stroke or 4 stroke weight from a brochure:
http://www.abycinc.org/standards/purpose.cfm#S30

JimMac, I would be happy to be your weight... I will move anywhere in the boat you need me. I can fight fish, hold things (preferably the beer) and I don't complain too much. With the proper amount of beer I will gladly sleep in the boat while docked. Just an offer .
Jeremy

You just have to admire and respect a designer whose solution to a trim problem is more beer.

After all he is from Belguim and went to school in Germany. He's probably tried a few different brands in his day! Myself can't forget some of those Belguim beers.

Tom

jacquesmm wrote: I will zip the Excel file and upload it if somebody is interested but the good news is that the design is right and the JimMac's hull is correctly built.

I would like see the spread sheet.

I will extract a PDF from it and find a place to upload it later today.

I find it interesting that this boat is so sensitive. Am I just making too much of it.

What if you only wanted a 25HP.. How would that effect this balance. Quite a bit I would think... Maybe it is only a matter of putting your gas in the back..


Oh I get it... a couple more 6pks... never take away always add..

mecreature wrote:I find it interesting that this boat is so sensitive.

It's that fine entry: smooth ride but less volume.
Always keep in mind that the hull shape is the same than the famous Simmons Sea Skiff, same behavior.

Whatever engine use, you can balance the weights by moving the fuel and battery accordingly.
PS: my engine weight includes all fluids and a heavy prop. Many manufacturers figures are for empty engine (no oils) and no prop.

Here are the files:
http://www.bateau.com/free/FS17_hydro_3.htm
is the hydrostatics file
and
http://www.bateau.com/free/LCG_FS17.xls
is the weight spreadsheet as an Excel file.
They are in metric and stripped down versions but correct.
The weight file is based on a big boat spreadsheet, disregard all the lines about cabin and etc.
I only did the longitudinal values because that is what affects the trim.
The formulas are in there, you can move weights around and see how it affects the LCG.

mecreature wrote:What if you only wanted a 25HP.. How would that effect this balance. Quite a bit I would think... Maybe it is only a matter of putting your gas in the back...

The boat will not be nearly as sensitive to weight changes at the stern compared to the bow.

jacquesmm wrote:It's that fine entry: smooth ride but less volume.
Always keep in mind that the hull shape is the same than the famous Simmons Sea Skiff, same behavior.

If I am not mistaken, the Simmons Sea Skiff does not have a self bailing cockpit, so it doesn't really matter how the boat is sitting at rest - the water is going to collect in the boat somewhere.

Ralph

UncleRalph wrote:
If I am not mistaken, the Simmons Sea Skiff does not have a self bailing cockpit, so it doesn't really matter how the boat is sitting at rest - the water is going to collect in the boat somewhere.

Correct. Simmons Sea Skiffs owners can't comment on drainage problems because there is no drainage.

Jacques _ Thank you for the time you put into trying to figure out my problem. I would be very interested in having access to the spreadsheet.
A couple of questions to clarify.
1. I assume the LCB ( longitudinal center of Bouyancy) is the same as the LCG (Longitudnal center of Gravity)?
2. The design LCB is 3,378 M or 11’ 1â€

JimMac wrote:Jacques _ Thank you for the time you put into trying to figure out my problem. I would be very interested in having access to the spreadsheet.
A couple of questions to clarify.
1. I assume the LCB ( longitudinal center of Bouyancy) is the same as the LCG (Longitudnal center of Gravity)?

Yes, that's how it balances. The boat will trim until the LCG is lined up the LCB.

2. The design LCB is 3,378 M or 11’ 1â€

I have not said to much on this subject till now just a few words at the beginning to try to make sure we were on the same wave length.

Now for my .02 on the FS17 which will be worth .00 by the time you read this.

The FS17 is a narrow waterline boat that does not compare to the seakeeping abilities of the other 17' boats that Jacque has designed. I would not build the FS17 it is just to sensitive to weights, I have bought 5 plans and never the FS17. For example the C17 with the upper panel removed has the same freeboard as the FS17 yet can handle more sea state. Both have about a 45 or so entry at the cutwater. The C17 is wider and more stable do to its width and can handle moving wights around better. The same is true with the OB17.

Hey if you want a basic boat with tiller steering go with the FS17 if not the added cost of making the FS17 into a console with gunwales go with the C17 center console without the upper panel or for an added cost the upper panel, depending on your fishing style.

For you guys building the FS17 now enjoy your boats just try to keep your fuel in the center section and enjoy your boats. As Jacque says there is no design flaw they are just sensitive to weight placement.

Again this is my Humble Opinion

Tom

Tom, I completely agree with you except that I would not have used the words "seakeeping abilities".
The FS17 is a seaworthy boat but as you point out very well, she is a much smaller boat than the C17. Because of that, the C17 is a more capable boat and for that same reason, the FS17 is more sensitive to weight distribution.
It's just the nature of the boat.
The design was started because people wanted a Simmons Sea Skiff for stitch and glue. That is what she is. A good and capable boat but a smaller boat than the C17.
She also cost less, require less labor to build.
All together, a valid choice as long as we accept the compromises that come with that program.

Thanks for everybody's input, strengthened my decision to go tiller with a 25hp and keep it simple, I'll probally save the wide gunwales for my C19 or C21, either way the FS17 will do what I intended, taking the kids out for some croaker, spot, flounder, trout ect. a inshore fishing boat

Daniel

Jacque when I said seakeeping=seaworthy I meant the ability to handle chop and heavy waves,

Totally agree and hope the builders understand that moving weights are detrimental to there benefit.

Tom

colonialc19 wrote:. . . either way the FS17 will do what I intended, taking the kids out for some croaker, spot, flounder, trout ect. a inshore fishing boat

Daniel

Don't misunderstand, she can go offshore. The FS17 has the same hull than the Simmons Sea Skiff and can do everything that boat can, even more thanks to the self bailing cockpit.
Tom and I were just having some small talk about the meaning of some words but we agree.

Yes totally, she is fully very capable as designed and builders should not be leary of building her but recognize that she has her quirks and deal with them as they make plans to build her. Listen to the Designer! I do love her looks.

Tom

Dang, should I wear a lifejacket when I splash my FS17? I'm looking forward to getting my boat in the water

This issue of high and dry scuppers when a boat is at rest reminds me of a funny story of my late friend Danny. He was doing some guiding on the west coast near here some years back. Day one or so he came down to the dock after a heavy rain.

Anyways he has a look at about a 17 foot skiff sitting nose down with about 6" of water in it. He figured he'd make himself usefull and bail it out before he headed out in the boat he was running. He looks around and finds a plastic grain shovel (they are used lots around here and make fast work of bailing). He steps into the stern of the skiff with his gumboots on and the water runs back toward him and drains out of the scuppers in the stern and the boat spewed the water in like 10 seconds. He says he felt a little silly there with customers looking at him with the grain shovel in hand....

Turns out Danny didn't realise the boat had scuppers. And someone had left a couple of crab traps in the bow.

I think if I was in this position, with tanks already installed too far foward I'd first consider just filling a 5 gallon bucket with water and leaving it at the stern when its on its mooring....

I didn't mean to talk down the boat at all, she will be put to the test

I'm used to calling offshore 15 or so miles and futher, thats just me and the area I'm in.

I still plan on the occasional trip to the 3rd and 4th islands of the Cheasapeake Bay bridge tunnel, ( about 12 miles from Lynhaven inlet )

I'm sure the boat will handle anything I have the cahoona's to take it out in

Daniel

colonialc19 wrote:II'm used to calling offshore 15 or so miles and futher, thats just me and the area I'm in.

Daniel

Me too. Offshore was when we go 20+ to the stream I doubt I would ever take my boat oceanside. Even if my 17 footer was shaped like a box with a V hull and "seaworthy" as heck its still only a 17 footer

Me too


I will go as far as the Florida Reef only when we have flat seas.


Bushmaster

ColonialC19, CLT is only about 12 miles from Rudee Inlet. Thats what I'm shooting for on a good weather day. What do you think, too much? Also thinking of using the kiptopeke ramp to cut the CBBT distance in half to fish it all.

frazoo

Fazoo the ride to CLT from Rudee should not be a problem just keep a listen and look at the weather. Run for home when she starts picking up and you'll be fine. Have been out of Rudee before(many, many years ago) not a bad place to fish out of. I think the key to this boat is going to be the learning curve on what she can handle. That mey take a few months of several of you using her after launch. Each will have different past experience and some will take her out further than others comfortably.

Tom

On a good day Rudee and the ocean look like a flat calm lake. I would have serriously paddled my canoe out of it last time I was there!!! HOWEVER within 3 hours we had a few 3 footers rolling around and I was glad I was in a big boat I wouldn't hesitate to take the FS17 out of there on a good day Just start with short distances until you get the feel of the boat. I think she will handle more than I care to (I need a puking emoticon here)

Frazoo, NO problem going out in the FS, but use common sense. Fisherman were complaining of the jetski's running around out there last summer.

The eastern shore is a safer bet for the highrise, 3rd and 4th, if the weather is even close to being choppy.

Hope to see you out there