What premium would I pay moving to a convertible/sportfish vs a trawler?

[Enyar]

I understand that at hull speed a trawler/motoryacht/sportfish will have similar fuel efficiency. That would be my plan for 80% of the time. However, there are times when I would like to bump it up to 18-20 kts and I would really appreciate the cockpit/fishing amenities that come with a sportfish.

I'm trying to figure out where the increase in cost would really come in (other than when running fast). If the cost is similar at hull speed, does the premium only really come into play when it comes to rebuild and maintenance time? And also paying a premium on interior space dedicated to the larger motors?

Otherwise, why wouldn't you want the option to go fast for very little penalty at hull speed?

 

[ranger58sb]

From reading, I guess that our fuel "economy" at hull speed -- at roughly 4 GPH or less -- has been around 2X what a trawler of similar size might be seeing.

Yes, maintenance on larger -- turbo, aftercooled, etc. -- engines will generally be higher, but I've sorta decided to ignore that part of the trade-off.

-Chris

 

[psneeld]

The price you pay is mostly weight carrying capacity....and also speed.



My 1988 Convertible Ran 20 kn ots, 1 NMPG. My 40 foot trawler runs 6.3 knots at 3-3.3 NMPG.


Plus less storage in convertable designs.

 

[ranger58sb]

Hmmm.... on plane at 22-ish KTS, we were always closer to .75 NMPG, and somewhere between 1.5-2.0 NMPG at hull speed... all dependent on wind, current, tides, etc.

Yes, maybe less storage. We actually had almost more than we needed... but of course I found ways to fill it all up...

Another thought is maybe about staterooms, in some cases. An aft-cabin trawler might offer 2 forward and one aft cabin, whereas a sportfish/convertible may have to be longer to give the same accommodations. Or if there are 3 staterooms forward, there might be some differences in size/space of each.

-Chris

 

[Prospective]

I would say that boats designed to plane ride like crap at hull speed. I have a 43ft sportfish and I hate running hull speed in anything less than calm conditions. In 1-2ft chop that my boat would eat up on plane, the ride at hull speed is awful. Getting tossed and pitched around.

As to $$ costs, for a given size boat, a planning boat is going to need higher horsepower engines. MUCH higher horsepower. So, as was pointed out, you've got turbos, aftercoolers, and other pricey gear and the engines are much bigger for given size boat. And the high horsepower engines are working MUCH harder. So maintenance intervals are more frequent and more intensive. Not to mention, a lot of trawlers are single engine. So, with a planning boat you're likely dealing with two engines.

I think about this often. One day I'd like to have a retirement boat in the 55ft range. But as much as I like sportfish, the cost to maintain the engines would break me. You're talking 1500hp 12 cylinder beasts with 1000hr maintenance costs running $25k or more. Compare that to a single engine trawler or even a semi-planning boat like a flemming with lower HP engines where I think costs will be lower.

 

[ranger58sb]

I think I'd temper that a bit... more like "sometimes ride like crap...

Certainly a serious chop can put the kibosh on a comfortable ride, but then again much depends on direction period, etc...

Then again, we don't hesitate al that much to get on plane if that'd be better. The counterpoint to that is that we've also had to stay OOF plane in some circumstances... timing ourselves through the peaks and troughs...

-Chris

 

[Prospective]

Agreed, all boats are different. But a boat designed to plane is designed to have it's best stability on plane. I think that is definitely true of boats like yours and mine. My boat is almost always more comfortable on plane, at varying speeds depending on sea state.

I've had times where I've told myself and my crew that a nice slow ride to our next destination would be fun. Then we get out and find ourselves being tossed around by a 2ft chop and we all agree it's time to get going.

Only exception is when sea state is so severe that being on plane isn't possible. Then you've got to run hull speed and deal with it. But I generally try to avoid those conditions!

 

[Enyar]

I would say that boats designed to plane ride like crap at hull speed. I have a 43ft sportfish and I hate running hull speed in anything less than calm conditions. In 1-2ft chop that my boat would eat up on plane, the ride at hull speed is awful. Getting tossed and pitched around.

As to $$ costs, for a given size boat, a planning boat is going to need higher horsepower engines. MUCH higher horsepower. So, as was pointed out, you've got turbos, aftercoolers, and other pricey gear and the engines are much bigger for given size boat. And the high horsepower engines are working MUCH harder. So maintenance intervals are more frequent and more intensive. Not to mention, a lot of trawlers are single engine. So, with a planning boat you're likely dealing with two engines.

I think about this often. One day I'd like to have a retirement boat in the 55ft range. But as much as I like sportfish, the cost to maintain the engines would break me. You're talking 1500hp 12 cylinder beasts with 1000hr maintenance costs running $25k or more. Compare that to a single engine trawler or even a semi-planning boat like a flemming with lower HP engines where I think costs will be lower.

Fleming is the magic word right there. I'm looking at an old Hatteras, which has a semi planing hull like the fleming. I'm effectively looking for the poor mans Fleming. It wouldnt run 30kts, more like the fleming and it's not a 12 cyl beast, it has Cummins QSM11. Certainly a beast compared to a 120 hp Lehman but still seems managable for my budget.

Just need to figure out if the extra motor + extra hp is worth the squeeze compared to the trawler life.

 

[Ken E.]

My boat, a Hatteras convertible with a planing hull, runs cleanly at hull speed burning about what Chris does, around 4 gph for both engines. At around 7.5 knots, the hull is running flat with no squat, leaving a moderate wake and bow curl. I like this speed for a number of reasons, so much so that I re-powered from old, tired Detroit 8v71's which would plane the boat to Cummins 6bt 210's which won't. Going slow in the PNW has the advantage, in addition to less fuel burned, of being less likely to hit logs and other debris in the water because there is more time to react. Making the long trip to Alaska each year slowly just makes more sense. In terms of resale value and impact of the boat not being able to plane with these engines, I really don't care...I have the boat as I want it.

Regarding livable space on a sportfish design versus others, there's no doubt that there's less interior room...but there is the benefit of a big open 'patio' area for nice weather, and great room for fishing and other outside activities. I personally prefer the sportfish layout over others for this reason. We move into the salon when it rains.

 

[Woodland Hills]

What model Hatteras are you looking at with a semi-planing hull? I believe there was a 44’ or 45’ double cabin with a sort of dual purpose hull, but all the rest were pure planing or displacement (LRC).

We operate a Hatteras planing hull motoryacht as a cruiser at hull speed and it works very well in any sea as long as the stabilizers are running!

 

[OldDan1943]

Fuel efficiency must include weight on board.
Fill the tanks, keep all your 'creature comforts' and tools onboard, next time you have the boat hauled, ask the lift operator how much does your boat weigh.

I installed a 'flow scan' on my N46 trawler. My current AT34 has a flow scan read out on my Vessel View. I am not saying they were/are 100% accurate but, they are close. If you are planning a trip and down to the last 1/3 in the fuel tanks, rely more on the sight glass on each tank. Just my worthless opinion.

 

[rsn48]

I would say that boats designed to plane ride like crap at hull speed. I have a 43ft sportfish and I hate running hull speed in anything less than calm conditions. In 1-2ft chop that my boat would eat up on plane, the ride at hull speed is awful. Getting tossed and pitched around.

I have experienced worse ride when going slower in choppier conditions but worse than that for my boat (Sedan Cruiser) is the steering. At displacement speeds 7 knots or less, I have to constantly correct on a straight line course. But once up on plane and moving at 12 - 14 knots or more, you don't need hands on the wheel for the boat to go straight.

 

[MYTraveler]

IME, efficiency and ride will depend greatly on hull design. Contrary to some comments above, my boat handles as well at hull speed as it does planning, but it is a heavy boat so planning comes at a high price (about 60 gph to do 18 knots, vs 7 gph to do 8.5 knots). As far as interior room, nothing is lost to accommodate bigger engines when the salon is over the engine room. In fairness, my boat is not a "trawler" style boat (at least not as far as I understand that term), but it does offer passage maker range (2300 gallons of fuel) and safety off shore, but and is well suited for fishing.

 

[Woodland Hills]

The rudders of planing hull boats are never big enough at hull speed. Ours is OK in everything but following seas when the small size is apparent. I’m thinking of adding some fiberglass to give a fishtail shape to the trailing edges. That should give more authority.

 

[Enyar]

IME, efficiency and ride will depend greatly on hull design. Contrary to some comments above, my boat handles as well at hull speed as it does planning, but it is a heavy boat so planning comes at a high price (about 60 gph to do 18 knots, vs 7 gph to do 8.5 knots). As far as interior room, nothing is lost to accommodate bigger engines when the salon is over the engine room. In fairness, my boat is not a "trawler" style boat (at least not as far as I understand that term), but it does offer passage maker range (2300 gallons of fuel) and safety off shore, but and is well suited for fishing.

Thanks. The Nomad would be my ideal boat. I really like the older Elliotts too.

 

[Enyar]

What model Hatteras are you looking at with a semi-planing hull? I believe there was a 44’ or 45’ double cabin with a sort of dual purpose hull, but all the rest were pure planing or displacement (LRC).

We operate a Hatteras planing hull motoryacht as a cruiser at hull speed and it works very well in any sea as long as the stabilizers are running!

It's my understanding that most of the older Hatteras are more of a semi planing design. I like the 45 46 and 52 convertibles.

 

[Ken E.]

It's my understanding that most of the older Hatteras are more of a semi planing design. I like the 45 46 and 52 convertibles.

The Hargrave-designed 45 and 46 convertibles built in the 1970's, like my boat, are hard chine, planing hulls.

 

[lwarden]

We bought our boat for Southern California where a turn of speed is appreciated since it's so far between interesting places to visit. But since we've been operating this summer in the PNW I can really see the desire for a trawler up there. My boat seems to ride pretty well either at hull speed or cruising in the low twenties. I don't have a Flowscan but from what I can see my fuel consumption is about 2.8-3 GPH at hull speed and about 20-25gph cruising at 18-20 knots.
I'm finding myself running more at hull speed just for the shear lack of stress and find it makes the trips more enjoyable. That and I don't have to worry about throwing a huge wake and pissing some of you guys off as I pass.

 

[Larry M]

We’re full displacement and sip fuel. Hull speed is 8.4 knots and we cruise at 6.5 to 7.2 knots. When we bought Hobo she fit our cruising style perfectly. This past summer (after 13 years and 20,000 plus miles) coming back from the Bahamas, a planning hull and with ability to go 3 times our normal cruising speed would have been nice. The weather was absolutely perfect. We still love Hobo but you can’t have it both ways. Every boat’s a compromise.

 

[Codger2]

Otherwise, why wouldn't you want the option to go fast for very little penalty at hull speed?

I faced that question about 6 years ago and opted for a 42' Ocean Alexander sedan that was happy at 8 knots and could scoot when desired to 20 knots. I never looked back!

The boat is at 13 knots in the video.

 

[RonR]

The Premium is more smiles per mile.

 

[OldDan1943]

I faced that question about 6 years ago and opted for a 42' Ocean Alexander sedan that was happy at 8 knots and could scoot when desired to 20 knots. I never looked back!

The boat is at 13 knots in the video.

Yea, looks pretty, I do hope the captain has sense enough to slow down prior to passing smaller boats.

 

[markpierce]

Hope you "go-fast trawlers" guys are aware of the effects of your wakes.

A "go-slow" (one knot below hull-speed) trawler:

 

[MYTraveler]

Thanks. The Nomad would be my ideal boat. I really like the older Elliotts too.

The newer Elliotts are even better. For the first time since taking delivery of my current boat, I am thinking about having a bigger Elliott built.

 

[Enyar]

The newer Elliotts are even better. For the first time since taking delivery of my current boat, I am thinking about having a bigger Elliott built.

I didn't know they were still being built. Got a website? I couldnt find anything.

 

[MYTraveler]

I didn't know they were still being built. Got a website? I couldnt find anything.

I confused Nordlund and Elliott and hold both in high regard. Nordlundboat.com. It is the 88' that caught my eye.