Cruisecraft outsider 575 porpoising 135 optimax

[NAGG]

Okay I just assumed a little extra weight in the bow would help hold in deeper in the water when It was rough. I cant seem to trim the nose of the boat into the water as much as I would like. Other boats I have owned have been heavier in the bow and have seemed to ride better, or at least had the capacity to dig the nose in when the going got tough. I don't seem to have that option at the moment as the boat seems to flighty up front.

I've got to say - I'm with you here ...... my 5m Seajay with the old 70 yammi & big (60kg) battery in the nose never porpoised . I swapped the motor to a 100 yammi (more weight) & moved the battery back a meter plus added a duel battery really changed the balance . I ended up with a boat that porpoised at mid revs (not bad but you had to trim down) . At speed no issues .
I've just fitted a foil & get to test it over the next 3 days in flat water and at sea ...... So we will see what the outcome is.

Chris

[Hillbillyfish]

I assumed cruise craft wouldn't be interested as it was purchased as a second hand boat. Nagg let me know how you go with your new foil added. I'm thinking I may have to look at outboard wedges to help me get more trim (nose down).

Cheers

[Gon Fishun]

Could it be under powered? Read on the net 135hp to max of 150hp. I have no knowledge of this model boat, but looking at them on the net they appear to need a large motor.

[Hillbillyfish]

It seems to have plenty of power. Gets on the plane easily. Sits on 68km wot, so I have assumed the power is okay.

[terryc]

Years ago when i had a cruise craft i phoned the manufacturers for some advice and found them really helpful

[Hillbillyfish]

Okay i'll give them a call. Anyone in particular I should speak to?

[gofishin]

Okay i'll give them a call. Anyone in particular I should speak to?

They are normally a very helpful manufacturer and are very passionate about their boats. I have heard many times about them helping people who have bought 'pre-loved' CC's.

Ask for Justin or Nathan Nicols (owners) or Peter Benston, there are a few others who are very helpful too, but their names escape me ATM. Kevin Nicols (dad) is not around much any more but he is also very helpful if you get hold of him on the off-chance.
Cheers
Brendon

[bden]

I have a 135 opti running the same prop and when I first got it it also did the same thing. Solution and that was 12 years ago fit a SE300 foil. Problem solved. No issues since.

Brett

[Hillbillyfish]

I put a se300 on it a month ago and didn't seem to help. How high above your keel is your cav plate? Also do u have extra weight up the front of your boat??

[Andy56]

Would a jack plate help? It would move the center of gravity back giving you more trim control. You can optimise engine height too. The yanks are heavily into jacks where as we ignore them. Just my thought to what seems to be a long running issue.

[GBC]

You've changed 2 things instead of one. Personally if a foil fixes something on an 18 ft boat, it's masking a symptom that could be fixed better. Get rid of the foil - they don't need them, no good hull does.
Second, the flightiness of the bow and not being able to jam the nose into chop is all about the hull shape - they have broad shoulders and a planing plank - they do that. Tabs will help - expecting to fix it with trim won't. It's a (relatively) little boat and won't stay in the water if you try to run it on the plank in anything but small chop. I had that hull for a few years. They are great at rest, brilliant at slow planing under 20 kts, and a pain in the arse trying to keep up with sig/haines/seafarer equivalent length hulls in chop or offshore - it won't do it, they fly out of the water, but that's how they were designed. You'll come home in a cyclone at 18 MPH in one while seafarers are pointing their noses at the sky.
It sounds a lot to me like you are trying to trim against the planing plank trying to get it to do something it just won't.
As others have said, drag it down to the Hemmant factory or to the showroom and see the boys - you won't find a company with better after sales service. It isn't under powered with a 135. The 550's (same hull) mostly ran 115's.
I'd also run a straightedge along the rear of the hull where it was repaired and confirm it is still true.

[Andy56]

I am thinking about what Chris Tucker said. "porposing happens when the center of gravity is forward of the center of lift".
He then explained that pods are used to bring the center of lift forward. Surely another angle to this is to move the center of gravity back by using a jacking plate. This allows the motor to sit much higher and further back in clearer water The leverage on the plane would make it more responsive to trim. and less to "bump porposing"
I am no expert here, but seems logical to me. The only limitation is the bum heavy look.

[Hillbillyfish]

Hi All, So I just thought id give an update on progress for eliminating cruise craft outsider porposing. So firstly I lifted the motor 1 hole and this helped reduce the proposing, however I still couldn't get the nose of the boat into the water enough. Then I added a "fast tail" hydrofoil and instantly noticed the extra trim I received. I went offshore last week and what a difference, boat just cruised through the 0.5-1m chop with ease no banging at all, the v of the boat is now doing what it was intended to do. The boats ride has been completely transformed. thanks for everyone's help and insight.

[Crunchy]

Foils - awesome bits of kit, wish I could get one.

[Scott79]

Hi All, So I just thought id give an update on progress for eliminating cruise craft outsider porposing. So firstly I lifted the motor 1 hole and this helped reduce the proposing, however I still couldn't get the nose of the boat into the water enough. Then I added a "fast tail" hydrofoil and instantly noticed the extra trim I received. I went offshore last week and what a difference, boat just cruised through the 0.5-1m chop with ease no banging at all, the v of the boat is now doing what it was intended to do. The boats ride has been completely transformed. thanks for everyone's help and insight.

Just curious mate, after raising 1 hole did you try the SE3000 Hydrofoil or just go straight to the "Fast Tail"? Was there a recommendation from someone to try the Fast Tail or was it just a bit of good fortune?