GRP boat stabilization

Icom · October 10, 2013, 09:41:07 CET

Hello all,

Need some help with stabilizing my boat. Cuts through water very well but unfortunately it rolls like crazy even when underway. Sometimes it goes into a side dive and steering it to correct position becomes quite a difficult task. The boat is a buccaneer 145 (14.5Ft) Deep-V Hull. The back side is actually quite flat.

Any recommendations will be really appreciated. Im sure there are many out there who have or had the same problem.

I have attached a photo of the front side of the boat for ease of reference.

Granitu · October 10, 2013, 12:25:54 CET

Mur kellem lil mario tal buccaneer - il gudja u jghinek. Qed nimmagina li ha jkollok bzonn xi trim tabs imma hull tieghu daqsu hadd ma jista jtik risposta ahjar.

halop · October 13, 2013, 10:49:41 CET

jidher li mil qed tamilek ax ghandha quddiem maluq hafna al wisa taha, meta taqa min mewga tfittex fejn trid hi.u anke jkollok xi hadd quddiem jicaqlaqlek jaf tkun perikoluza,jien kelli l istess problema bl stabilizers mal mutur solvejt 3 kwarti tal problema mil bqija dejqitni u nehejta wara 8 xhur li xtrajta gdida ...il problema ax made in malta,kullhadd jamelli jiftilhu u miskin il klijent

shanook · October 13, 2013, 14:23:31 CET

imbad xi xtrajt Halop

The_Gaffer · October 13, 2013, 16:35:17 CET

I had a bucanneer that suffered the same faith. It has nothing to do with trim tabs, trim tabs would actually make this worse. I'm guessing you have a inboard, although you didn't say so. You need to make your rudder slightly longer than it is. i bet you are experiencing this when you make slight turns, right? Fabricate your rudder to be just slightly longer in length than your prop. Just 1 inch would be enough. This is also a problem qith single screw engines.
It is a condition associated with having wide assed, flat back side bottom boats. It is not definitely not a deep V, it may have a sharp V entry, but definitely not deep V. Deep V hulls are measured by the degree of dead rise at the back. Bucanneers are relatively flat at the back, which facilitates boat planning and thus reduces the need for high HP engines.

savioursajdbis · October 13, 2013, 16:37:11 CET

andek miktub shanook ,marino atom 450 honda bf50 . Icom stabilizers mal mutur ha jejnuk hafna uwa vera li ha titlef xi 5 knots imma wertet ukoll tista titiltja il mutur waqt il mixi hali rasa ma izomix baxxa .

Icom · October 13, 2013, 20:31:51 CET

Thanks guys for the input. The boat is powered by a 50HP High Thrust Yamaha outboard. The engine has stabilizers too. This happens when in a slight turn and also when straight ahead. Problem is if it nose dives its really hard to get it back in horizontal in choopy seas! One thing to point out is the front end is a bit light in fact at the moment im experimenting with sand bags to help keep the bow down. This did help a bit but obviously to the detriment of carrying some dead weight. Im considering building a custom fuel tank to go in the bilge area up front.

Keep the ideas coming maybe someone comes up with a good solution!

The_Gaffer · October 14, 2013, 10:14:59 CET

I have also noticed you added a cabin to the boat. Is that custom built, or supplied by Buccaneer?
It could have an impact on the way the boat moves forward as this has changed the boat's centre of gravity, hence the crazy rolling and sideways dive.
Above all, have you spoken to Charlie at Buccaneer, I'm sure he would be able to sort this out, unless of course, that cabin you added is not Buccaneer standard

Icom · October 14, 2013, 13:01:19 CET

Hi Gaffer,

The cabin was built by Buccanneer. Havent spoken to Charles yet about this problem. Now i have an even more serious problem to deal with. Was out this morning and since the seas where very calm i was tempted to go WOT. Did so from Qawra to Sliema when all of a sudden next to Sliema pitch the engine overheated! I must admit that im under revved in fact im waiting on a propeller replacement which should be in either tomorrow or Wednesday. Apart from that, now that this has happened, im going to pull up the boat and have the impellor changed and the thermostat inspected. Engine was bought second hand!

benri · October 14, 2013, 16:48:08 CET

Icom, Did you check whether a steady flow of water was coming out of the engine? If there was a steady flow, it's no use changing the impeller. Did you tilt up the engine and check whether you ran into something (eg a plastic bag) that might have blocked the water intake? I don't think being under revved has anything to do with overheating.... over revved a different situation.

Granitu · October 14, 2013, 17:10:02 CET

Quote from: Icom on October 14, 2013, 13:01:19 CET
Hi Gaffer,

The cabin was built by Buccanneer. Havent spoken to Charles yet about this problem. Now i have an even more serious problem to deal with. Was out this morning and since the seas where very calm i was tempted to go WOT. Did so from Qawra to Sliema when all of a sudden next to Sliema pitch the engine overheated! I must admit that im under revved in fact im waiting on a propeller replacement which should be in either tomorrow or Wednesday. Apart from that, now that this has happened, im going to pull up the boat and have the impellor changed and the thermostat inspected. Engine was bought second hand!

If you still have the thermostat, they are prone to foul - check it out and if your trusted mechanic allows you take it off - do so. Thermostats are really applicable for engines working in cold weather where the sea is at 0-3 degrees celcius, not really for malta. where surface temperature is the most minimun 9 degrees celcius. I had received such recommendation from my own mechanic when i owned a boat with an outboard - on a yamaha.

Do you rinse your outboard cooling system after use? you could have some salt deposits in the cooling system (if you rinse after use you should have none). that could be another reason.

Another problem could be the electric system - but prior to this I would check the temperature of the water coming out of the pee hole.. if its way to hot for you to withstand feeling it you have a cooling issue for sure.

Icom · October 14, 2013, 18:41:51 CET

@ Granitu

Your idea of removing completely the thermostat makes a lot of sense. The one i have is intended to open above 60C which is not very far away from our ambient temperature. I might consider doing so. With regards to flushing the engine after use, i wish i could do so but how can i do it when the boat is at sea and i dont have a supply of fresh water!

Granitu · October 15, 2013, 09:09:38 CET

Quote from: Icom on October 14, 2013, 18:41:51 CET
@ Granitu

Your idea of removing completely the thermostat makes a lot of sense. The one i have is intended to open above 60C which is not very far away from our ambient temperature. I might consider doing so. With regards to flushing the engine after use, i wish i could do so but how can i do it when the boat is at sea and i dont have a supply of fresh water!

Can your outboard take flushing attachments?

IF yes, carry a 25ltr jerrycan mixed with some salt removal mixture (you can use white vinegar - its cheap and as good) and after using it flush your outboard at idle speed.

Funnliy, salt deposits only form when the outboard is not being used. if you use it everyday, it would not be convenient to flush it but if you use it 2 times a week, i think flushing the cooling system is important.

halop · October 15, 2013, 13:24:52 CET

atom marino stabli hafna ma tantx anda qieh v imma worth it dejjem il bnazzi nfittex u petrol bir riha lol probably qijat naqra overpower il power mhux fuq it toqol u kemm tkunu persuni jitqies izda fuq it tul u wisa

guido99 · October 15, 2013, 13:40:37 CET

Quote from: Icom on October 14, 2013, 18:41:51 CET
@ Granitu

Your idea of removing completely the thermostat makes a lot of sense. The one i have is intended to open above 60C which is not very far away from our ambient temperature. I might consider doing so. With regards to flushing the engine after use, i wish i could do so but how can i do it when the boat is at sea and i dont have a supply of fresh water!

Your outboard engine is designed to operate at a specific operating temperature. This is controlled by the thermostat.
Removing the thermostat will cause problems in 2 stroke and 4 stroke engines.

The main problems you will get are, Inefficient fuel burn due to the engine components not reaching operating temperature and fouled ( even in a 4 Stroke) plugs due to incomplete fuel air combustion.
A four stroke will "make oil". This is when unburnt fuel passes into the crankcase and dilutes with the engine oil and causes the "Oil" level to rise instead of decrease. This has happened to me on my Honda BF50a when my thermostat got stuck open and i didn't realise, until it was time for an oil change which I do twice a season on the water. When i removed the dipstick it was completely covered in the oil petrol mixture with liquid visible in the dipstick tube itself.
Also important to note that the thermostat is there to control coolant flow into the coolling passages. This is done by restricting the coolant flow to allow it to transfer heat from the engine block onto the coolant efficiently. Removing the thermostat will not allow the coolant stream to transfer heat from the engine as this will flow too fast and only a fraction of the engine heat will be transferred. This will then result in the engine overheating when running a high rpms.