Mainship Speed - Real Life Examples

[SMLBill]

Folks, we are torn between two separate Mainship 40 alternatives. One has a Cat 3126 380hp single and the other has twin Yanmar 240's. I know from experience that the Cat WOT speed is about 13-15kn. A broker tells me that he got 20-22kn top speed at WOT out of the twin Yanmar and cruises at 15-16kn. Does anyone have direct, personal experience with WOT and Cruise on a Mainship 40 with twin Yanmar 240's? If so, what is reality? Thanks in advance for your insight!

 

[Pete Meisinger]

I am against twin engines in a trawler. However, since this particular Mainship is not a true trawler I guess the choice is totally yours.

I believe your experience of 13 - 15 kn is correct. I also believe the broker saying a twin Yanmar with total hp of 480 would hit the speeds he describes.

Booth estimates being correct and honest, what do you want? Economy of the single or the horses of the twins. Here things get complicated, see previous discussions of twins vs singles.

A 40 foot Mainship traveling at 22 knots would definitely suck some major fuel.

I see this simply as an extension of twins vs singles.

pete

 

[Shrew]

What is the objective?? If you're looking for speed, then a trawler isn't it. WOT is somewhat irrelevant, since that isn't the speed you'll be travelling. Cruise speed of 9-11 vs cruise speed of 14-16.

Are you looking for shorter travel times, less fuel burn? Please don't say "outrunning storms". Unless you're cruising at or above 40 kts are you even thinking about being able to reasonably outrun a storm.

A tow is about the same speed as getting home on one engine on a single engine boat.

 

[DavidM]

There is no way in hell going from 380 to 480 hp (in twins no less) will let you go from 13-15 to 20-22 kts. I think your Cat 380 speed is consistent with what Steve Cyr has reported for his Yanmar 370 powered MS 400.

Steve quite rightly states that his boat is an under 10 kt boat, preferably 8-9 for better fuel economy. The twin Yanmars will probably give you a cruise of 12-13 kts and a wot speed in the upper teens. Don't cruise between 10 and 12 kts because you are pushing a wall of water to get over the hump at that speed and is hard on the engine.

Put another way the twins will cruise a little slower than the wot with the Cat 380. Pulling about 160 hp per engine at cruise is all you should do with the Yanmar 240s. So 320 vs 380 hp drops the speed about a knot.

David

 

[SMLBill]

My objective is to have the reserve power/speed to use when I may need it (making a bridge opening, getting to a marina before dark, etc). That is what I want to be able to do, at my discretion. I would typically cruise at hull speed, for fuel economy. I just want the option to get to plane (15kn+/-) from time to time, which I can't do with a single. What I would like to know is, IF YOU own a Mainship 40 with the twin Yanmars, what is YOUR actual experience with speed? Real world. Not from a chart. Thanks!

 

[ljk]

I have a 34 Mainship Pilot with the twin 240s. I cruise at 15-16 kts at 2900 to 3000 RPM. Wide open is 3400 RPM and 23 kts.

 

[Dougcole]

Our 400 with twin yanmar 240s has a wot of about 21 knots lightly loaded. At 2900 rpms, which is where I run it at fast cruise (about 25% of the time) we turn 14 to 16 knots, depending on load, sea state etc. At that speed we burn about 14 gph.

Over the course of of month long Bahamas trips, fast all the way across and back, slow most of the other time we consistently burn on average 9 gph. That includes about 150 hours of gen set run time.

 

[SMLBill]

Beneteau Swift Trawler Quality

Thanks everyone for the valuable information. If there are any other Mainship owners out there willing to share their experience, I would love to hear from them, too!

 

[Ski in NC]

I have sea trialed a bunch of Mainships in the 34-40' range, some twins, some singles. I too don't believe the Cat boat would be that much slower than the twin Yanmar boat. Maybe a couple knots at top end. It would surprise me if it was much more than that as a difference.

I found the single Mainship to be rather obnoxious above the slow planing speed. Lots of prop noise and vibration above something like 14kts. Can't remember if it was the same situation with the twins.

My opinion of these hulls is they are really nice at hull speed, but if you want to run faster than that, wrong hull.

 

[garmstro55]

I have a 2004 MS 400 with the twin Yanmars. I typically cruise at 8-9 knots, about 2000 RPM if my memory serves me (and it sometimes doesn't). I will run at 3000 RPM from time to time and I hit 16 or 17 kts or a little bit more depending on the current (hit 21 on the C&D Canal last summer with a following current). I don't think I have pushed it higher that 3000 as yet. At the higher speeds I have no vibration or excessive prop noise and, on the upper Chesapeake, the ride is quite comfortable unless we get a strong beam wind which does make the boat rock side to side a bit.

If you do some research, you will get lots of opinions, pro and con, about the 3126. I don't think I ever saw anyone complain about this Yanmar engine though, so, for me, I wanted the twins both for that reason and for maneuverability, as I was already used to twins on my other boat. Of course it means double everything, oil changes, props, gauges, transmissions, zincs etc. so there's that as a negative.

I bought the boat in September 2018 so my experience with the boat is somewhat limited, really only one full season.

Generally love everything about the boat. Like any boat, there are always things that need to be fixed or upgraded. What year are you looking at?

 

[SMLBill]

Hi Gary, We are looking at a 2007 MS 40, but also considering a 2005 Beneteau Swift 42. Each boat has a lot to offer. We prefer the layout of the MS, but there are many details we prefer on the ST. The ST in question is a bit more expensive, but is also in better condition. It's a tough call, but still clearly a "first world problem"... Bill

 

[garmstro55]

Bill, Kinda like buying a house, it seems the boat finds you instead of the other way around. We fell in "like" with the 390 but were wowed by the 400 with the better interior layout, the summer kitchen up top, faux teak and holly sole and a bunch of other features.

Good luck with your decision. Where do you plan on keeping her?

 

[SMLBill]

Hi Gary, That's why we keep coming back to the MS 40, too. We live in Edgewater, on the South River just outside Annapolis. That will be our home port. It looks like you may be close by! Bill

 

[markpierce]

My objective is to have the reserve power/speed to use when I may need it (making a bridge opening, getting to a marina before dark, etc). That is what I want to be able to do, at my discretion. I would typically cruise at hull speed, for fuel economy. I just want the option to get to plane (15kn+/-) from time to time, which I can't do with a single. What I would like to know is, IF YOU own a Mainship 40 with the twin Yanmars, what is YOUR actual experience with speed? Real world. Not from a chart. Thanks!

Going at hull speed is not efficient. Fuel consumption for me at one knot below consumes less than half the fuel at hull speed.

 

[Dougcole]

Going at hull speed is not efficient. Fuel consumption for me at one knot below consumes less than half the fuel at hull speed.

I find that drifting with the engine at idle to be the most efficient speed of all.

 

[Nomad Willy]

Doug Cole,
Don't think so.

You'd probably be amazed how fast you go at idle ... in gear.
Even if it's only one or two knots it's much faster than drifting. And in gear at an idle you'll burn less fuel because your rpm will be reduced. Fewer injections = less fuel burned.

Mark is right. Way too much is made of or implied about hull speed.

 

[arcadia]

I believe you may be looking at the 2005 st we traded in?
Did you make a decision yet.

 

[markpierce]

My engine mechanic likes the minimal noise my boat makes even at maximum (7+ knots) speed.

 

[SMLBill]

Not sure. What was her name? Nothing we've seen is called Arcadia...

 

[arcadia]

Our new 47st is called Arcadia.

 

[Pete Meisinger]

Hmmmmm, why would anyone want to burn close to 20 gallons an hour? That's like a hundred dollars an hour.

Hard to relate to my Albin burning maybe 2 gallons per hour.

I'm thinking of a new slogan. "It's the direction, not the speed"

pete

 

[Codger2]

Mark is right. Way too much is made of or implied about hull speed.

Finally! Reality about the infamous "hull speed" quotes.

 

[SMLBill]

What is the name of your prior boat? Is she Shay Shay?

 

[arcadia]

Yes. Family owned 15 years.

 

[rslifkin]

Hmmmmm, why would anyone want to burn close to 20 gallons an hour? That's like a hundred dollars an hour.

Hard to relate to my Albin burning maybe 2 gallons per hour.

I'm thinking of a new slogan. "It's the direction, not the speed"

pete

It's all about how much time life provides to travel and see things. Given enough time, I'd be very happy with a slow boat and the resulting savings in fuel. But for now, where the length of continuous time we can spend on the boat away from home is limited, we get to go further and see more by pushing the throttles forward (and telling my wallet not to look) for the stretches of travel where there's not much to see.

I'm sure similar constraints drive plenty of others towards faster boats as well. And then, of course, there are some that just like going fast.

 

[slowgoesit]

Yes. Family owned 15 years.

Oh oh, the broker's worst nightmare! The potential buyer is now in contact with the previous owner who traded the boat in! Heaven forbid, what will happen to the potential deal when the previous owner clears up the "fog of sale" that the broker has conjured up . . . .with . . . Oh my gosh, FACTS!


A friend of mine in Hawaii was looking at listing his boat at a broker in Honolulu. Part of the contract the broker wanted him to sign was a statement that the Seller agreed to refuse to have any contact with a potential buyer, and if contacted by a potential buyer he would refuse to speak to him/her, holding the Seller financially responsible if a deal didn't go through . . . He moved on . . .



Good luck in finding the right boat!