Stability?

hey guys,

 

took the project boatbot out on the water this morning, went well but a few thing I need to get my head around.

stability: the boat is pretty much empty. No fuel

tank in it or anything. Just engine and me and my othe rmate who came out this morning with me prob 150kg combine. We found that the boat is a good sea riding hull but I think it’s lacking in the stability region.

not sure that it’s pretry much a empty hull with a 170kg engine on the back only wouldn’t help it’s cause.

would love to get people thoughts and experiences on this and if they think when I add the 250l fuel tank in it that it all. The hullnis 6.2m 7.3LOA. 6mm bottom, 5mm side and transom with steel bar rolled keel

help 

Image Upload: 

Faulkner Family's picture

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 extra weight will put the

Sun, 2019-07-14 13:56

 extra weight will put the boat a bit lower in the water. the stability you mention , is it while driving or stationary. if while driving trim tabs would help 

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RUSS and SANDY. A family that fishes together stays together

Paul200990's picture

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Yes trim tabs are a must but

Sun, 2019-07-14 13:59

Yes trim tabs are a must but mainly at rest  

Faulkner Family's picture

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 extra weight in the hull may

Sun, 2019-07-14 14:02

 extra weight in the hull may help a bit as i said it will sit lower in the water. only speaking from my experience but i have only owned glass boats

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RUSS and SANDY. A family that fishes together stays together

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Date Joined: 17/06/10

When you talk stability

Sun, 2019-07-14 16:34

What exactly is it that is causing you concern, when you are at rest is the boat healing over at an alarming angle when you move over to one side with one or two people.
Is the boat at rest moving around wallowing (side to side movement) when you walk around the deck.
Is the boat pitching ie; when moving forward or aft to a great degree which is inconsistent with the amount you expect with the weight movement, bow diving or stern dipping when moving aft
From the photo (2) the boat seems to be sitting down on the chines in the water which to me is where they should be, just my opinion.

Paul200990's picture

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 It was just listing over

Sun, 2019-07-14 17:05

 It was just listing over while travelling and a lot of listing at rest when walking around the cabin.

drove well and cut through the water nicely. Just was abit unstable at rest and more listing than I am use too.

Paul200990's picture

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Just added two more photos.

Sun, 2019-07-14 17:09

Just added two more photos. Not the best but you can sorta see how high it sits and also from the transom, how much  does get exposed when rocking. 

Posts: 38

Date Joined: 25/03/10

 That hull looks similar to

Sun, 2019-07-14 16:58

 That hull looks similar to the old dolphin hull I had. Steering position well forward. When 2 or 3 people are are forward it was very unstable particularly in a following sea. When the Esky and people were at the rear it was fine. You can also trim the motor up a little also to help lift the bow up.

Paul200990's picture

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Yeah the boat is built by

Sun, 2019-07-14 17:11

Yeah the boat is built by Milton rear and Dave Jackman designed.

Milton is one of the founders of sea quest/razerline and assassins.

he built this boat after he retired for my supervisor at work in 2005.

its an unofficial assassin. Spoke to him on the phone about it and confirmed that it is an assassin design

z00m's picture

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Weight is as used

Sun, 2019-07-14 17:15

You should put the weight in it that it would normally have before you sea trial like that. If you want to ckeck it before you commit to building tanks and fitting it out then use water barrels.  

Think about how bar crusher ads a lot of ballast water to their hulls when in the water so they are more stable. I think you'll find as you add the correct weight to it like interior fitout, fuel tanks (not just the fuel), safety gear, wiring, electronics, esky etc you'd be up another couple of hundred kg and then your fuel, water and passengers would all add more.

Paul200990's picture

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Yeah for sure, I was just

Sun, 2019-07-14 17:35

Yeah for sure, I was just curious on how it went in the water today. Likes it a lot. Sounds abit hollow but that’s to be expected 

sunshine's picture

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Might want to consider a flooding kill tank

Sun, 2019-07-14 17:54

Adds heaps to stability at rest and drains very quickly as you take off through venturi action if pipe feeding it is large enough. I run a 6.8 seaquest but the kill tank has a threaded  bung so we can use the area as dry storage if heading out to the islands  

Paul200990's picture

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Hey sunshine, can you pm me a

Sun, 2019-07-14 17:55

Hey sunshine, can you pm me a pic of your boat layout if you have one. Trying to work out where I can put my kill also tank and curious on the difference with the deck design to mine. I don’t think there would be much difference since it’s built by the same people 

sunshine's picture

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Kill tank located centrally between the seats

Sun, 2019-07-14 19:01

i don’t have a photo on the iPad (only the outside after complete respray) but will look on the main computer when I get a chance.  It floods quickly and stabilises the boat brilliantly when drift fishing  

Paul200990's picture

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Hey sunshine, can you pm me a

Sun, 2019-07-14 17:55

Hey sunshine, can you pm me a pic of your boat layout if you have one. Trying to work out where I can put my kill also tank and curious on the difference with the deck design to mine. I don’t think there would be much difference since it’s built by the same people 

Posts: 497

Date Joined: 04/05/08

 More weight will get the

Sun, 2019-07-14 18:13

 More weight will get the chines sitting in the water making it more stable.Looks quite high out of the water in the photos.

Paul200990's picture

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Yeah that was my thought too.

Sun, 2019-07-14 18:55

Yeah that was my thought too. Sat real high  

Rob H's picture

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 Im confused!

Sun, 2019-07-14 18:47

 Im confused
This boat bought as a project,

then for sale,

then talked out of selling by a mate

then did a shoulder and was for sale again

Now it pops up with the same owner doing seatrials...

Cant keep up haha!

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 Give a man a mask, and he'll show you his true face...

 

 

The older you get the more you realize that no one has a f++king clue what they're doing.

Everyone's just winging it.

 

Paul200990's picture

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Haha yeah me either.My mate

Sun, 2019-07-14 18:55

Haha yeah me either.

My mate wanted to take it out and see how it went after I got the engine going.

hit the water nice :( now he is on my case about keeping it and putting a 200 on it 

now :( 

Paul200990's picture

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I got my eye on a nice

Sun, 2019-07-14 18:57

I got my eye on a nice seafarer vagabond hha 

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You forgot the bit about

Sun, 2019-07-14 19:41

You forgot the bit about cutting the roof off to make a centre console.  

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Date Joined: 09/10/06

 Ha. Was trying to sell the

Sun, 2019-07-14 20:53

 Ha. Was trying to sell the hard top separately also. I see your mates selling your quintrex on your behalf now. 

Paul200990's picture

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Yeah I don’t have social

Wed, 2019-07-17 10:55

Yeah I don’t have social media and he is on many more fishing pages than my misso 

rob90's picture

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 Dont forget hard top for

Mon, 2019-07-15 09:44

 Dont forget hard top for sale then pulls ad, then back up as combo sale with other boat then pulls ad then back up as loa 7.2 ali for sale. Haha cant keep up either

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 Hi my name is rob............. and I'm a........... fishaholic

Paul200990's picture

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 That’s what happens when you

Wed, 2019-07-17 10:54

 That’s what happens when you are adhd :) can’t make my mind up. Always have ideas 

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As alluded too above

Sun, 2019-07-14 19:10

I think when you get the bits and pieces added to the hull you will find that the hull will settle down to a very nice stable hull. The second lot of pics show it ridding with the chines just clear of the water line more weight will fix that, it looks like you have a great boat and should have some great times on the water.

Paul200990's picture

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Yeah maybe. Thinking of

Sun, 2019-07-14 19:15

Yeah maybe. Thinking of selling it, got shoulder surgery coming up and time after that to heal. 

scubafish's picture

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Shoulder

Sun, 2019-07-14 21:20

just had that done,rotator cuff 6 weeks before sling to comes off,up to 4/6 months physio.
lot of sleepless nights and drugs.
Regards boat,250lts (250kg) in middle of the boat will make a big diff basically that's 2 adults and 1 child as far as weight goes.centralizing the weight will work and make a big diff.
Have read somewhere that weight difference between ali and fiberglass is completely diff up to about 20ft,then it becomes similar.
There is a mathematical equation to get it right as far as water displacement and weight goes,also where the weight should be as far as front or back.
Trim tabs will assist in stabilization when moving and not at rest.

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Paul200990's picture

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Date Joined: 22/05/19

Yeah this will be my second

Sun, 2019-07-14 21:33

Yeah this will be my second reco on the same shoulder. Worst pain I have ever been in after surgery. 

Yeah im hoping so. Just gotta get the chines in the water abit more but im

thinking  once I put both batteries in there. A new 4 stroke (40kg) more than 2 stroke that’s on it now and then the fuel tank and everything else plus the trim tabs it should make a a huge difference. But can I be stuffed to do that is outweighing my thought of keeping it especially after the reco

Swompa's picture

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The boat will have been

Mon, 2019-07-15 07:57

The boat will have been designed to accomodate a fair bit of kit in the back such as the fuel, another battery, deck wash and so on. If the boat is empty, it won't be maximising its beam and be balancing on whichever side of them has the most beam. Essentially it is trying to be a Trimaran. 

My former brother in law purchased a copy of a Chivers 6.5maluminium build and at speed, it would flop from chine to chine. Needed more weight in the back to give it some displacement. 

More weight in the boat will have it digging far more of a trench and give you a hell of a lot more stability.

Think about 150 kg ingots along the keel that can be removed if you go out full. Right down against the hulli/keel line to keep centre of gravity low. You wouldn't have the first boat to need ballast.

Rob H's picture

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 Chine walking is the term

Mon, 2019-07-15 09:48

 Chine walking is the term for this

____________________________________________________________________________

 Give a man a mask, and he'll show you his true face...

 

 

The older you get the more you realize that no one has a f++king clue what they're doing.

Everyone's just winging it.

 

Swompa's picture

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Didn't know it was a thing!.

Tue, 2019-07-16 19:49

Didn't know it was a thing!. There ya go!

Paul200990's picture

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 I don’t think the hull was

Mon, 2019-07-15 10:32

 I don’t think the hull was deep enough in the water for the chines to properly do there  thing hahha

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 I'm more confused,  it reads

Mon, 2019-07-15 16:02

 I'm more confused,  it reads you dont have the fuel tank in it? Does it in those pics.

If that's the case lm not surprised its arse is still out of the water 

Paul200990's picture

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 Nah no fuel tank. Running

Mon, 2019-07-15 16:06

 Nah no fuel tank. Running the engine off a jerry can to tear it out. But I was curious to how much the fuel tank would help 

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 You selling the fuel tank?

Mon, 2019-07-15 18:22

 You selling the fuel tank?

Paul200990's picture

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 It came with a 140l poly

Mon, 2019-07-15 19:47

 It came with a 140l poly fuel tank. If I re power if I’m go n put a 200 on and gonna get a 350l one made up

But will sell the poly one if you want it 

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 Haha. Nah, you mite need it

Mon, 2019-07-15 20:06

 Haha. Nah, you mite need it if your selling the boat.

Paul200990's picture

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 Yeah only rippped it out to

Mon, 2019-07-15 21:41

 Yeah only rippped it out to have a look in the hull and transom