Marlow 65' seatrial vibration

The 1994 custom built trawler in the picture is 52 feet (58LOA), twin Lehman 135hp. Draft is 5', displ 90,000lbs. . The photo is from LMC. The owner built it for himself but never cruised.

Judy

Been slightly involved with a '04, 71' Explorer.
No vibrations. Smooth and fast.
She does have the exhaust deflectors.

Digging up a very old thread, sorry, but this was a fascinating read. What got me here is I am looking (online) at a Marlow 70' and am wondering if I should even bother to consider her at this point.

Here are a couple pictures. The props seem small and rather closely spaced, but don't seem to have the problematic tunnels mentioned in this thread. Not sure where the exhaust ports are (that lead to the cavitation / vibration mentioned above). The two ports on either side of the transom at waterline seem too small to be the main exhausts.

Thoughts?

Yes, now I see the tunnels very clearly. Thanks. Moving on...

Bryan

And ultimately the only way to find out if they were effective is through an intense and thorough sea trial and that likely requires an offer and money.

Wow, first time seeing this build out of the water. The prop placement reads of a cyclops. Even with the tunnels, how can those props not impact each other with wash?

David Marlow is a mad scientist. He can't stop. He is always looking for a little more or better, so no two boats come out the same. That means some are delivered with permanent issues that can't be corrected. He's knowledgeable and has a lot of ideas, but the execution is missing as he just decides he could do this or that and be a little faster.

I can't mention the boats name but it was a tall Marlow the owners loved. In the engine room, I could play half court between the in line Cats.
I have been studying that last bottom picture (post 86). These engines are way closer than the Marlow I was working on.
Was he looking for more dense water or a different ER layout when he brought the engines closer?
I can imagine NO room between the blocks per these pictures.

I've always enjoyed looking over Marlows at the dock. This Marlow on the lift, however, that's a cacophony of nonsense underwater. Those props so close together, neither with even the slightest opportunity to grab clean water...

Engine room of this particular boat. Cat 3406Es. Doesn't seem to be too bad, but I'm still not clear why the props are so close for a boat with an 18'4" beam.

I guess you Really need a stern thruster with the props being so close!

Lazzara used enclosed shaft housings on the C30s powered 84. They are supposed to reduce drag but Probably not by much since they didn’t use it in the C32s with larger shafts.

The 84 also has similar fences to prevent the exhaust from being sucked in by the props but it s also one of the few planning boats I ve seen without trim tabs.