Cruise 10-15kts with OB power under 30'?

[nwboater]

Has anyone transitioned from an inboard diesel trawler to an outboard powered boat? After 25 years of owning full-displacement diesel trawlers that have carried us on summer-long trips along the Inside Passage, SE AK, and down the west coast, I'm ready for a change of pace. We've relocated a big part of our life away from our island home and the marinas and boatyards I've depended on, so now I'm looking for a smallish outboard-powered boat that can be stored on the hard for part of the year and easily launched when back home.

This is a long way of asking...is there an OB-powered boat under 30' that will run easily at 10kts - 15kts? From what I've read, seems like most of these boats (Ranger Tugs, Jeanneau NC series, etc) either run at hull speed, 6-7 kts or at 22+ kts after getting up on a plane, but slog along when running between 8-20 knots. Is there maybe a simi-displacement boat/hull someone can recommend where the sweet spot for cruising is around 10 knots? I don't want another inboard diesel or outdrive unit -- I'm wanting ease of ownership that I "believe" will come with a boat powered by new OB engine technology, drive-by-wire steering, and electronic engine/speed/fuel instrumentation. At the moment I'm liking the Jeanneau NC 895 but it falls into the category of "slogging" when running between 7-20 knots...any suggestions from experienced outboard owners? Also, am I daydreaming to wish for "ease of ownership"?!

 

[Gdavid]

That is faster than hull speed but too slow for most pocket cruisers to plane efficiency. A stripped down, flat bottom boat like a Carolina skiff could do it, but by the time you fit a hull that size with the accomodations and fuel you need, it wants to plane out at 18 knots minimum. A displacement cat like a glacier bay could meet your need, they made two or three different models of 26' cuddy cabins. I don't know the difference among them.

 

[RT Firefly]

Greetings,
Hahaha....A cat was just what I was going to suggest. We recently adopted a World Cat (Glacier Bay edition) 2770 (built on the Glacier bay 26' hull).



World Cat does NOT make a cuddy version in any of their models although due to the popularity of the GB 26' hull they continued with that hull and cuddy for a few years after the two companies amalgamated.


GB did make a number of cuddy/cabin models in the 26', 30' and 34' range. Anything with the last two numbers being 70, 80 and 90 does have accommodation. Eg: 2680, 3080 etc.


Our 2770 is somewhat spartan in that there is a cabin with a queen bed, head and no cooking facilities. The GB 3080/3090 is a better "weekender"


Expect 1.5 to 2.0 mpg. This GB is in fact a 3090 and not a 3080 as advertised with a completely enclosed PH (the 3080 has a canvas back bulkhead). She was originally advertised in the $200K range about 4 months ago.
https://www.yachtworld.com/yacht/2008-glacier-bay-3080-coastal-runner-8276507/

 

[Nomad Willy]

If you can find a boat light enough it won’t need a very high angle of attack .. running angle or?

Also having mostly a flat bottom will further widen the speed window of “slogging”.

A narrow hull will lower the wetted surface and also reduce drag and the power to plane at relatively low speeds.

A boat with these features will be most likely to get what you ask for but will be a bit (or worse) hard riding or pound as they say.

But long and narrow may alow you to have a bit heavier boat and be as easily driven as you prefer. Old motorboats from the twenties may have the desirable hull form that will fill your needs.

Just saw RT’s post and think the 25’ Albin may work for you. Some come w a trailer when sold. If 8-9 knots will do the earlier hull will do. Later model A25’s have a wider transom and will go faster running quite level.

Look up “Atkin boat plans” and see Ben Peck .. a 24’10” older V bottomed boat design that will easily fit your requirements.

 

[mvweebles]

30-foot and 10 knots is a dead zone for efficiency. Either go hull speed, or do planing speed (17+). At 10kts, efficiency will be no better than at 20kts but with twice the engine hours.

Look at the Rosborough 265. Nice little boat. Inboard, I/O, or OB versions.

Peter

 

[twistedtree]

I'm not sure what else you are looking for in the boat, but here are some thoughts:


Grady White makes an excellent boat. They are generally more day boats vs overnight boats, and really not cruising boats.


At the last Seattle boat show I saw that Back Cove is now offering a 30-something boat with outboards. It was pretty interesting.


Cutwaters are good looking boats, I think, and many available with outboards. That said, I've heard some horror stories of Cutwater and Ranger Tug boats (same company), so would approach with great caution, and a guilty-until-proven-innocent mindset.

 

[Jeff F]

The Sisu 22 has caught my eye. Nice small downeast style boat.

 

[nwboater]

Thanks all for the feedback. A few mentioned power cats…the Glacier Bay being one example. Interestingly, I just stumbled onto the Aspen C-107. Outboard power, 34’, asymmetrical hulls. The Aspen website shows a power/speed/fuel consumption chart that suggests a continuous speed curve giving 10 knots at just 2500 rpm from the single 200hp Yamaha. These are not inexpensive boats…a used 2019 was priced at $380k. Price aside, I think a small power cat may be in my future

 

[Catbird]

Consider a C-Dory. I owned a C-Dory 25. It happily cruised on plane at 10-13 knots.

 

[nwboater]

Consider a C-Dory. I owned a C-Dory 25. It happily cruised on plane at 10-13 knots.

Yes! Thanks for reminding me…I’m familiar with the C-Dory 22, but I see that the 25 has an enclosed head compartment. A requirement if I expect my wife to join me. Also good to know that it runs on plane at a lower speed than the Ranger tug or Jeanneau [emoji106]

 

[sjisailor]

The Aspens are beautiful, efficient, and stable -- and easy to see in the PNW area, they deliver out of Anacortes Cap Sante, or visit the factory in Burlington if I recall correctly. Although the cat thing is polarizing due to the head configuration and low headroom in the berth. (By "polarizing" I mean, "Admiral vetoed them" )

As for Ranger Tugs and Cutwaters, you should ask at the TugNuts site. Folks there will be happy to share their observations. In the PNW, it rarely makes sense to go above 20 knots for very long in my opinion, and 10-15 makes a lot of sense, so I expect they will have things to say. https://www.tugnuts.com/portal.php

 

[O C Diver]

You might look at Downeasters in general. My 35' Bruno and Stillman would easily cruise at 10 knots and plane around 12 to 14 knots depending on load. Not sure what makes and models might fall into that hull shape. Between 7 and 9 knots the hull was pushing water and over 20 knots would require a ridiculous amount of power as it's not an optimized planing hull with a large keel.

Ted

 

[nwboater]

The Aspens are beautiful, efficient, and stable -- and easy to see in the PNW area, they deliver out of Anacortes Cap Sante, or visit the factory in Burlington if I recall correctly. Although the cat thing is polarizing due to the head configuration and low headroom in the berth. (By "polarizing" I mean, "Admiral vetoed them" )QUOTE]



Agreed about the awkward sleeping arrangement (for us older couples

 

[nwboater]

You might look at Downeasters in general. My 35' Bruno and Stillman would easily cruise at 10 knots and plane around 12 to 14 knots depending on load. Not sure what makes and models might fall into that hull shape. Between 7 and 9 knots the hull was pushing water and over 20 knots would require a ridiculous amount of power as it's not an optimized planing hull with a large keel.



Ted

Ted, you’re right about some Downeasters but they are a rare sight here in the PNW, especially with OBs.

 

[Jeff F]

You might look at Downeasters in general. My 35' Bruno and Stillman would easily cruise at 10 knots and plane around 12 to 14 knots depending on load. Not sure what makes and models might fall into that hull shape.

Agreed. The Sisu 22 I mentioned earlier had the same designer.

Eastern Boats makes a range of downeast outboard powered boats, including several variations of the Rosborough 246. https://www.easternboats.com/

 

[Shrew]

The problem with 10-15 kts is it is the most inefficient speed to travel unless your LWL is long enough that that is the range of your theoretical hull speed. (56 - 125 feet is where 10-15 kts lands. BTW).

On a small OB powered boat, that is the highest fuel burn in the curve, and the stern is squatting so badly, the boat feels like you're riding a wheelie.

 

[Jeff F]

On a small OB powered boat, that is the highest fuel burn in the curve, and the stern is squatting so badly, the boat feels like you're riding a wheelie.

I think that's an overly broad statement. It's certainly true for planing hulls, but lots of downeast designs are designed to cruise at 2-3 x hull speed, and do it very well. My experience with them is that there really isn't a hump to get over.

 

[rslifkin]

Even with planing hulls, the speed at which you get over the hump and onto a clean plane varies significantly with design, implementation of trim tabs, etc. Some faster planing hulls need more than 3x S/L to get onto a clean plane, while others get past the plowing stage and over the hump (nose drops, wake changes to a clean planing wake) at lower speeds (although the wake will still get smaller as the boat gets higher in the water at higher speeds).

Using my own boats for an example, with no trim tabs and a total weight of ~450 lbs, minimum planing speed on our 12 foot dinghy was ~12 kts and adding much more load would lead to not getting over the hump at all. Assuming an 11 foot waterline, that puts minimum planing around an S/L of 3.5. However, after adding trim tabs to help lift the stern, it planes much sooner. With that same 450 lb weight, it's cleanly planing around 8.5 kts (the wake is still taller than at higher speeds, but it's over the hump and the wake shape remains the same with increased speed). That's an S/L of just over 2.5. Add another 200 lbs to the dinghy and minimum planing speed is up to about 9.5 kts, or close to an S/L of 2.9.

The big boat is a 38 foot planing hull, but it's a fairly slow planing hull (no lifting strakes, forward sections are fairly full and rounded, has a keel, hard chine but no chine flats aft of the mid-point of the hull, and relies on large trim tabs for stern lift to plane). Waterline is 33.5 feet and I'd say it's cleanly on plane by 14 kts, maybe as low as 13 kts. Between hull speed and there, it plows significantly. At 14 kts, that's an S/L of just over 2.4. The wake gets a little smaller in height as you increase speed, and I'd say the handling starts to change a bit and the ride gets a bit more lively once you get above 18 - 19 kts (S/L of 3.1 - 3.3), but right around that range is max continuous on the engines anyway.

 

[nwboater]

Today I visited the C-Dory factory in Bellingham, WA. I looked over the 25' Crusier and liked what I saw. But what really caught my attention was the Tomcat, a 25' catamaran. And lucky me, one of the owners, Mike, offered to take me out onto the bay for a ride in a demo boat. It was windy with a 2-3 chop, yet the Tomcat just bumped along at an easy 8-10 knots. There was some slapping but overall the boat was steady with zero wallowing. On the return, with the wind and waves on the stern, we picked up the speed and the ride was unlike anything I've experienced (I only know full-displacement trawler boats). We were cruising along at 20 knots with the twin 150 Yamahas running at between 2,700-3,000 rpm. They were remarkably quiet! This boat was set-up with an aft helm station, which made it easy to maneuver inside the marina and for docking, even in the wind. I am sold on these small cats

 

[darkside]

No need to get over a hump if the boat is displacement.
Perhaps something like this?
Same NA as ours and a lot to like.

https://www.trademe.co.nz/a/motors/boats-marine/motorboats/listing/4162004432?bof=ZGh17mfz

 

[tpbrady]

I had a 22 C-Dory for 5 years and a 25 C-Dory for 4. The 22 would cruise very efficiently at 11-14 kts. The 25 on the other hand was most efficient at close to WOT. The 25 was stern heavy is the best I can say. But getting 3+MPG at 28 MPH was great if the water permitted. The 22 would get 5 MPG at the slow speeds in good water.

Tom

 

[markpierce]

Being a former sailor, traveling at six knots has been fast enough for me.

 

[FWT]

Well, there might be a solution to part of your stated issue, but not not the other part.

The solution part is in the desire to cruise in the teens while avoiding being in the dead zone of efficiency. The Camano hull has some design differences that give it a smooth fuel burn curve up to about 15 knots. There is an old sales YouTube clip out there on the hull design that explains it. Just know that at about 15 knots the boat handles a bit twitchy, as it seems to generate a bit too much lift. Its built today as the Helmsman 31.

Per Helmsman, with a Volvo 225hp diesel it burns about 12 gph at 13 knots. That might be WOT speed with that engine.

I don't know that this solves the ease of ownership issue, and it definitely isn't an outboard solution. Just throwing this out there on the off chance it sparks interest.

 

[Marco Flamingo]

Today I visited the C-Dory factory in Bellingham, WA. I looked over the 25' Crusier and liked what I saw. But what really caught my attention was the Tomcat, a 25' catamaran.

When reading this thread, I kept thinking "Tomcat, Tomcat." You got there. Go to the C-Brats website with any additional questions. Lots of knowledge. Little bickering. Sometimes (rare) a "for sale" posting.

Mark

 

[Hippocampus]

Being a New Englander my vote is for the Eastern 27’ Islander. Has a liveable interior for the admiral, very fishable. With twin 150 yamies or Hondas is quite efficient at the speed range you want. Eastern has a rep as a quality builder and the lobster and commercial fish guys use them. Made in new hamster. See a bunch around the east coast don’t know if used ones are around where you are.

 

[BroadCove]

Lots of good advice on here already, including the "dead zone" and the utility of catatmarans in this application. If you prefer a monohull, as others have referenced, weight and transom deadrise are going to be the keys to being able to plane at a slower speed.

I may have missed this, but I don't think anyone has mentioned the fitness of an aluminum hull here. I had a 26' Pacific for more than a decade, powered by a single Suzuki 250. Lightly loaded, I topped out just shy of 40 kts. Most effecient cruise was 22-28 kts, at about 2.5 kpg. But I could plane at 14kts with tabs down. It wasn't really efficient, so I didn't do it unless the seas dictated a slower speed.

But, if you went a bit bigger, say 30', with twins, and a hull with less deadrise (I think I was 14 degrees at the transom), you might find the sweet spot you're looking for. aluminumalloyboats.com is a good reference.

 

[rslifkin]

Good point on the mention of deadrise. The hull on my boat (which was previously described in this thread) is only 10* deadrise at the transom.

 

[Sweet marie]

I may be in a unique position as my 29’ trailerable trawler started life out with a diesel and I have since converted it to outboard power. I could not be an happier that I made the change. Some of it was for economic reason, the Volvo Penta D4 was very expensive to maintain property, even when I did all the work. The other engine related reason is I was just tired of snaking around and cutting my hands up every time I had to perform any work on it. My other, and maybe most important reason is that the engine box was so large on the boat it rendered the cockpit useless. Performance wise I am very pleased. The 210 hp diesel pushed the boat up to 30 knots and cruised well at 15-18 knots returning about 2.3 kmpg. With 150 Mercury 4 stroke I lost about 5 knots on the top end, but my most efficient cruise speed remained the same. At cruise my fuel burn is identical. I did lose some efficiency at hull/ trolling speeds. As a side note I did all the work myself, and the sale of the VP diesel paid for the new engine and rigging. I used to frown on outboards and always leaned towards diesel power, but in the right sized boat range I don’t think modern outboards can be beat.

 

[Sweet marie]

Whoops, I may have inadvertently hijacked this thread with my post. I thought the original post was comparing diesel vs outboard power on small trawlers. I guess that's one argument against reading in the bathroom when in a hurry.

 

[twistedtree]

Good point on the mention of deadrise. The hull on my boat (which was previously described in this thread) is only 10* deadrise at the transom.

How does the transom deadrise play into this?