Vibrations during sea trial

I was referring to the sniping at each other that various members seem to take on as a mission.

Less expensive in the long run, way less expensive than throwing parts at the problem and multiple haul-outs to chase whims.

Rich at Advanced Mechanical and Andy at DATUM in Fort Lauderdale have always been my first choice and are professionals.

Getting a job done right is often far less expensive than doing it wrong and the additional damage caused. And that's before even putting a value on time and stress.

Marmot is absolutely correct and there are a number of qualified vibration analysis specialists to choose from in South Florida.

It takes less time and money to do it right the first time than it does to do it over.

While true, given the OP's other issues, I would look at resolving those first. The vibration could be coming from his poor running engine.

It sounds like it can be done during a sea trial with out a haulout. Can you put a number on it? Like say $200 / hr for 4 hours? $500 / hour for 8 hours? What is typical? At what size vessel does it become economical.

Call them directly for that kind of information.

It becomes economical the minute it is beyond your knowledge, experience and skill level. Much like any professional service.

Not really. I have no doubts about the professional service. There aren't many of us on here that can pull a prop, shaft and coupling. Rework, true and balance the same and realign the shaft. There are many good yards and prop shops that will and can do that. And that will fix most of the problems. I've got a pretty good idea what that would cost to have done. If it costs $1k to have the vibration survey done that's one thing. If it costs $10k or more to have it done I'm more likely to give it the yard the first crack. On my boat I could replace all the hardware for that.

One would assume to do the complete job would take roughly the same amount of time per drive train regardless of the size of the boat. Same number of basic data points. So there should be a ball park figure available. What is obviously economical for a yacht the size Marmot deals with will probably be unrealistic at some point as you go down in size. "Less expensive in the long run" but probably not for a 36' Carver.

As Marmot suggested, call them for a quote. But then understand it may well be for just part 1 as they can't quote repairing the problem until they figure out what it is.

I would assume, or at least hope, the OP got a sizable discount based on the worst scenario since he went on and purchased the boat knowing about the vibration. Hopefully large enough to cover the repairs.

I guess this is one of those things that everybody says you should do but nobody actually does. Nobody seems to have any idea what it costs. I don't have any vibration issues so I'm not calling them just to inquire. I was just looking for real world experience for when/if I or one of my friends has an issue.

From Datum's web site:
DATUM can offer this service to the commercial shipping, mega-yacht and shore based industrial fields. As we learned earlier in the thread the OP apparently has a 37 Silverton. Nice boat but not exactly "mega-yacht" So not a likely match for Datum.

Anyone who has had to deal with a vibration problem knows it can get into a lot of dough very quickly with no certainty of correcting the problem. The cost can be difficult to reconcile when working on a relatively inexpensive boat. Nobody has any idea what it cost to fix a vibration because until you know what's causing it you don't know what to fix.

Actually, he number of owners doing so is growing rapidly as labor and parts costs continue to rise. The number of technical services providing vibration analysis is growing as well ... most people would conclude that someone "actually does."

Nor does anyone know what your grocery bill will be next week or how much your next pair of shoes will cost. It is a foolish person who would estimate the cost of a job on a boat he knows nothing about and the price for attendance is something you need to get directly from the provider. Call and ask, phone calls are cheap.

Silvertons vibrate for the same reasons as Feadships, the analytical tools used to find the source are the same. The scope of the survey and time required may be far far less.


Having used both the service providers mentioned and knowing them professionally for several years, I would never make that assumption and certainly never tell anyone what they might be available to do or for what price.

..Does the vessel have an engine syncro ? was it on and working correctly ? if not, you may have just experienced a vibro caused by unequal prop speeds, not uncommon when engines out of sync.

Very common cause on the older motors with auto synch in the control head. You can easily over ride the system.
My choice would be to align the motor, re-lap the prop on the shaft, tighten up the zinc and go for a test run.

Sounds like the OP bought the boat. Hopefully they will have a SMOOTH ownership