New 6M HT boat porpoising

I have fitted wedges to boats with some success, but they are not as effective as tabs. I look at your pics and notice the substantial flat along the centreline, which I assume develops and widens from the forefoot back, like a long triangle. I wonder whether that is contributing to the issues.

 

You are absolutely correct.... That is exactly how the bottom is.

 

Maybe next time don't buy a Chinese boat. Especially considering you live in a country full of great boat builders. I think you would find a NZ brand far more willing to stand behind their product.

 

Okay.... After trying a few props I used an american brand "Rupture" with good size rake and cup and improved dramatically but got even better once I installing her with bennett trim tabs. Finaly she is going great. No thanks to Atomix NZ. I ended up taking the advice of a prop designer/manufacturer and it paid off thank goodness.
Thank you all for your help

 

I wonder if the the trims rabs helped, or the props. I had a problem like that before and the trim tabs fixed my problem.

 

Would you believe The prop did make a huge difference ... Incredible, I would have never thought that a prop plays such a big part. What I believe my final prop did was, it gave my boat a a good grip on the rear with abit of transom lift. I tried approx 8 different props 3 blades and 4 blades....before I got the performance. What I also learnt was that your prop might be running within the recommended rev range (wot) but doest mean will give good performance. Pitch....Cup and Rake makes all the difference.

 

HOw did the new best prop effect speed and rpms?

 

Revs were well within the range and speed wasn't bad ...... But trim tabs made the speed even better..... by approx 6klms.

 

Sounds like there was a design flaw in boat hull/engine placement. I had a very fast boat, 70+knots. Past 60 it would porposie, not a fun thing. Tabs and wings on the drives fixed it. One thing I didnt figure at the time was the life being generated by the motors. It ran faster becuase the engines stayed in the water.
Here in Florida the really fast boats are using K-planes now to put some leverage on the downforce.

 

Choice bro.

 

Hi Atomix, hey I know you posted a while back but an Atomix 600 HT has come onto the market and I was considering buying it used. I followed your reports in sorting out your porpoising but you didn't give any information on the Rupture propellor you struck gold with. What was the spec of the prop? 3 or 4 blade and what diameter and pitch. Any help would be massively appreciated....

 

Hi Atomix, I'm Currently looking at purchasing the 600 HT, After sorting through a few teething problems how are you liking the boat ?

 

Hi. Ihave the same boat. Alot to get used too. I have trim tabs installed on my boat and with the touch of a button it planes out perfect and does not bounce at all. This is the best boat i have ever owned and been in. Absolutlly love it. Hope this helps.

 

lol at the trim tab position! 9" square.

lol at the single axle trailer!