Sailboat to Trawler Conversion

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The point some seem to have missed is this fellow, DeepSea, clearly walks to the beat of a different drum to the majority. And he has this old sailboat, which is past its best by date as a sailboat, but wants the satisfaction of converting it to something else that at his time in life would be more useful, and easier to use.

But he wants it to be THIS boat, not some other old has-been he might have been able to pick up cheap. Scooby he is not. Also, if he did that, what would he do with this boat..?

He wants to be able to sit back at some later time and tell folk that he converted an old sailboat he had, to this motor boat. Let's not even call it a trawler because even though most of our boats are also not trawlers, this boat of his will be even less so.

DeepSea, all I can say is go for it, taking on board some of the warnings given already, but be aware this forum is not going to be a mine of information on how to do what you want, but will only offer plenty of why you should not do it. Sorry, but you will have to use your own ingenuity and do your research from boat builder sources on line, staying away from forums, because as you found on the sailboat forums, they won't have much positive to offer either.

But hey, keep us informed. We will ALL be interested in how it all goes, for sure. And hey - you might even surprise some of the doubters...or not..? ☝️ :D
 
To who - the bathtub?
I was not referring to the op's vessel as a bathtub, I was referencing an actual bathtub ;)
I could have used a ski boat or an inflatable boat in the same analogy.

You must be from BC where they put small outboards on bath tubs and race. Some are so modified you can’t tell they were once bath tubs. But you call anything a BT here and someone’s gonna think it’s his boat. Beware flying things past your ear.
 
Enter
terminal trawlers

A picture should come up.
I love this TT. Yup the one w the round ports on the back of the PH.
Excellent example of a converted trawler.
However it looks like it’s not addressed the stability problem. Probably just needs some big bilge keels.
 
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A bit offensive re the bathtub Simi.

And if it has the essence of a trawler it is.
Heavy, non-planing, fair range … but it may not be a trawler w an OB. I say that and know that if one put an OB on a 25 Albin .. I think that’s a trawler but it’s lacking trawler essence on three counts.
1. Not heavy.
2. Lacks the trawler look.
3. Only moderate range.

There’s an iffy range of trawlerness. There’s a “Finn” boat on this forum that is deep into the iffy range .. but I’d but at least inclined to call it a trawler. Re the OB power I’d say hull bottom aft and speed range says much more about trawlerness than OB or not. But not many OB boats will have heavyness in their soec’s.




But here on the forum I can (or you can) talk about a specific boat repeatedly and use the word trawler. Few will call me out and many more will think badly about me and think of me as a horses ass.

But speed I think shoots more boats out of the trawler name that anything else IMO. If it planes it’s not a trawler IMO. But many will disagree … mostly those w boats that look like a trawler but know their not .. because they plane. And planing boats are not heavy.

Don’t misunderstand me. I’m not saying weight is a virtue by itself. Weight used wisely is great but just plain heavy is almost always sinful IMO. But in a lumpy sea weight does a lot for comfort. But I know of no boat where weight serves that purpose intentionally. That is just adding weight cuz less people complain.

What if I was to design and build a boat that tic’ed all the boxes of trawler but had a planing hull. I still wouldn’t call it a trawler.




I like the way you think Willy. My conversion will be slow (non-planing OB), heavy for a 21 footer (added bottom ballast for comfort and stability), trawler looking? How much can I do with a 21 footer?
Deep Sea
 
Some on here have said you can call anything you want a trawler.

I'd think what's most important is what do you want to do with it when done. 21' is awfully small. Putter around sheltered water, 1 or 2 people. Head, galley, and sleeping area. I'm guessing outboard powered. Not much room for enclosed steering.

What will you end up with that you don't have or can't do now ?? Other than no sails I don't see any advantage. But still you can always do it for the doing of it...




You are exactly right. All I want is for me and my mate to putter around in sheltered waters. Head, small galley, and sleeping area. All I have now is an unusable hull. I plan to put her to good use. All I need to do is to give her some TLC in the new conversion.
Deep Sea
 
Deep Sea,
Weight alone even if significant won’t buy you the kind of stability you want. You need a keel or bilge keels to dampen the roll movement. With the wrong timing of beam seas you could roll yourself silly w 3 toms of ballast. You should also know that “ballast to dampen roll” may be better along/under the sheer line. The idea being that you may be further away from the CG. That’s where the designer of the Albin 25’s told people to put ballast in the owner’s manual.

But I think you’ll be best served by sizable bilge keels in the middle (or a tad inbd.) of the turn of the bilge. Good to make them so the boat will rest on them when the tide goes out. When heeled sailboats can fill up w water over the rail, into the cockpit and into the boat from there. I thought about that w my Willard.

Yes your boat will be slow. But consider that there’s quite a difference between 3.85 knots and 4.25 knots. With fullness at the ends you’ll not only gain significant speed but the ability to carry more weight with’in a given length and beam. Consider all the things you’ll wann’a have on your boat. Like me you’ll prolly not have microwave converters or TV’s in your boat. But you may have other weighty things like spare anchors, rodes and fuel for a heater. How-a-bout another house battery?

The ability to carry weight in a boat is a good thing. Any weight that you don’t need is not.
 
The point some seem to have missed is this fellow, DeepSea, clearly walks to the beat of a different drum to the majority. And he has this old sailboat, which is past its best by date as a sailboat, but wants the satisfaction of converting it to something else that at his time in life would be more useful, and easier to use.

But he wants it to be THIS boat, not some other old has-been he might have been able to pick up cheap. Scooby he is not. Also, if he did that, what would he do with this boat..?

He wants to be able to sit back at some later time and tell folk that he converted an old sailboat he had, to this motor boat. Let's not even call it a trawler because even though most of our boats are also not trawlers, this boat of his will be even less so.

DeepSea, all I can say is go for it, taking on board some of the warnings given already, but be aware this forum is not going to be a mine of information on how to do what you want, but will only offer plenty of why you should not do it. Sorry, but you will have to use your own ingenuity and do your research from boat builder sources on line, staying away from forums, because as you found on the sailboat forums, they won't have much positive to offer either.

But hey, keep us informed. We will ALL be interested in how it all goes, for sure. And hey - you might even surprise some of the doubters...or not..? ☝️ :D




Thanks for the kind words Pete. I build small wooden boats as a hobby. I'm currently in the process of building Jeff Spira's 14' Seneca but I've never converted a sailboat hull to motor power. I joined this (and other forums) to learn the good, bad, and ugly. I feel that I'm getting it all, and learning a lot. The good stuff is good but I'm hopeful that the negative stuff will help keep me from making mistakes and getting into trouble. I've gleaned a lot of good info for my conversion from this thread already.


I think some of the sailors here have a tendency to stray from my purpose for this conversion. I love the build! I can't sail anymore (1st mate restrictions). I want to repurpose an unusable hull to a slow moving mini cruiser for sheltered waters. I don't worry about resale value as I've given all of my previous builds away to friends and family.


Deep Sea
 
Great info Willy. Yes, along with repurposing most of the original keel into bilge ballast I certainly plan to have not only a sizable keel but also a pair of sizeable bilge keels to help with roll and stability. Cabin will (in the current plans) be of 3/8" sides and 1/4" roof making for a very light top end. No there will be no microwave or TVs. LOL. We like to look at the water and passing scenery. I will definitely carry 2 anchors but a second house battery, hummm...Hadn't thought of that but a good idea.
Deep Sea
 
I had the opportunity to buy a trawler with a sail. It was 33 feet long, 8 ft. wide, aluminum hull with a small diesel that chugged along at 7 knots and 15 mpg. It had a stabilizing sail. To this day I regret not buying that boat.


Sailboats are trawlers: trawlers with a stick; the sail is rarely used.


On the Illinois River, we conversed with a sailboat crew doing the Great Loop. The masts were lashed to the deck. They thought it was a perfect Loop boat. We met another with mast removed, again on the Illinois. That crew had no plan for reinstalling the mast until they completed the Loop and sold the boat.
 
sail to trawler

Sure is. Spent a few years sailing her and looking forward to a few years motoring her.
Deep Sea

===============================

I specialized in "lost" causes, there is no project that simple I cannot complicate.
Few years ago did the opposite, had a Nimble Vagabond 20,pilot house or mini trawler, since I have always been a sailor (still am, sail a Cape Dory 30 MKII), after the first year asked several forums about converting to sail, everybody agreed could not been done, lots of technical explanations, and the more was told why could not been done the more determined I was.
Eventually had her rigged as a sloop, with roller furling on both head and main sails Bark sails that ordered precut from SailRite and sewn, together, learned to make sails during that time.
Was the prettiest boat ever seen, when stopping at transient places, somebody always had a comment, was truly a sight.
Every comment and opinion expressed here from a technical or practical point of view more likely correct, but we are not logical, nor practical, otherwise we will not be sailing or boating.
Go for it if your heart is on it.
By the way, I am in this forum although still sailing my time is coming up and trawler is there for me, haven't jumped yet but more likely have a season left the most, after that trawler here I come.
 
I hope you will post pictures of this journey. Really curious to see the project as it moves along. Good luck.
 
Another possibility?

At least 75% of the sailboats we see on the water (Pamlico, Pungo, Neuse, Rivers, Pamlico Sound, ICW, etc.) are under power - no sails up. We call those a "Motor Boat on a Stick". Why not just enjoy the nice design of the Cal 21 for what it is, save the money, add whatever additional power makes sense. I had a 21' San Juan - a smaller/lighter sailboat, and we did an 8 day cruise from New Bern, to Oriental, Belhaven, Bath, back to Oriental then New Bern. Tight accomdations, but it beats staying home or day sailing. (Saw a small trawler on the trip, light bulb went off, began Trawler dreams right then.) Power was a 4 1/2 hp British Seagull, but we sailed most of the way, except Hobucken/Bay River ICW canal. Havng a centerboard all the way down on those waters often is a great idea even under power - short, steep chop in moderate wind on those shallow waters with long fetches.

Assuming you have an outboard already, going higher up hp might not get you much additional speed, so check your actual speed against calculated hull speed.

Keeping up your sailboat to maximize potential sale price, and saving the money might lead to your having a nifty trawler later on. I see a razor sharp Atlas 25 on the water often - sort of a lobster boat/trawler variant. Saving up for one of those on the used market and selling the Cal might be the best outcome down the road. Check them out at Atlas's website or Yachtworld.
 
At least 75% of the sailboats we see on the water (Pamlico, Pungo, Neuse, Rivers, Pamlico Sound, ICW, etc.) are under power - no sails up. We call those a "Motor Boat on a Stick". Why not just enjoy the nice design of the Cal 21 for what it is, save the money, add whatever additional power makes sense. I had a 21' San Juan - a smaller/lighter sailboat, and we did an 8 day cruise from New Bern, to Oriental, Belhaven, Bath, back to Oriental then New Bern. Tight accomdations, but it beats staying home or day sailing. (Saw a small trawler on the trip, light bulb went off, began Trawler dreams right then.) Power was a 4 1/2 hp British Seagull, but we sailed most of the way, except Hobucken/Bay River ICW canal. Havng a centerboard all the way down on those waters often is a great idea even under power - short, steep chop in moderate wind on those shallow waters with long fetches.

Assuming you have an outboard already, going higher up hp might not get you much additional speed, so check your actual speed against calculated hull speed.

Keeping up your sailboat to maximize potential sale price, and saving the money might lead to your having a nifty trawler later on. I see a razor sharp Atlas 25 on the water often - sort of a lobster boat/trawler variant. Saving up for one of those on the used market and selling the Cal might be the best outcome down the road. Check them out at Atlas's website or Yachtworld.

^^^That is what I meant by don't do it. The Cal 21 is a fun boat as is. Use your talents to bring an old trawler back to life.
 
===============================

I specialized in "lost" causes, there is no project that simple I cannot complicate.
Few years ago did the opposite, had a Nimble Vagabond 20,pilot house or mini trawler, since I have always been a sailor (still am, sail a Cape Dory 30 MKII), after the first year asked several forums about converting to sail, everybody agreed could not been done, lots of technical explanations, and the more was told why could not been done the more determined I was.
Eventually had her rigged as a sloop, with roller furling on both head and main sails Bark sails that ordered precut from SailRite and sewn, together, learned to make sails during that time.
Was the prettiest boat ever seen, when stopping at transient places, somebody always had a comment, was truly a sight.
Every comment and opinion expressed here from a technical or practical point of view more likely correct, but we are not logical, nor practical, otherwise we will not be sailing or boating.
Go for it if your heart is on it.
By the way, I am in this forum although still sailing my time is coming up and trawler is there for me, haven't jumped yet but more likely have a season left the most, after that trawler here I come.[/QUOT



I don't really understand any of the negative input that you got converting a small trawler to sail. Motor sailors have been around a long time. Essentially, that is what it sounds like you ended up with. What did you use for a keel and ballast under sail or did you use small sails and light winds?
Deep Sea
 
===============================


I don't really understand any of the negative input that you got converting a small trawler to sail. Motor sailors have been around a long time. Essentially, that is what it sounds like you ended up with. What did you use for a keel and ballast under sail or did you use small sails and light winds?
Deep Sea
--------------------------------
we speak the same language, "small sails and light winds"!!!!
Just wanted to enjoy both the challenge and the "under sail" sensation.
If you have difficulties understanding the negatives, imagine The Wright brothers!! a flying machine? Cannot be done!
 
At least 75% of the sailboats we see on the water (Pamlico, Pungo, Neuse, Rivers, Pamlico Sound, ICW, etc.) are under power - no sails up. We call those a "Motor Boat on a Stick". Why not just enjoy the nice design of the Cal 21 for what it is, save the money, add whatever additional power makes sense. I had a 21' San Juan - a smaller/lighter sailboat, and we did an 8 day cruise from New Bern, to Oriental, Belhaven, Bath, back to Oriental then New Bern. Tight accomdations, but it beats staying home or day sailing. (Saw a small trawler on the trip, light bulb went off, began Trawler dreams right then.) Power was a 4 1/2 hp British Seagull, but we sailed most of the way, except Hobucken/Bay River ICW canal. Havng a centerboard all the way down on those waters often is a great idea even under power - short, steep chop in moderate wind on those shallow waters with long fetches.

Assuming you have an outboard already, going higher up hp might not get you much additional speed, so check your actual speed against calculated hull speed.

Keeping up your sailboat to maximize potential sale price, and saving the money might lead to your having a nifty trawler later on. I see a razor sharp Atlas 25 on the water often - sort of a lobster boat/trawler variant. Saving up for one of those on the used market and selling the Cal might be the best outcome down the road. Check them out at Atlas's website or Yachtworld.


Thanks for the heads up on the Atlas/Acadia 25. Just about what I have a vision for in my little 21.
Deep Sea
 
Thanks for the link OC. I've seen "Winnie the Pooh" on another site. Love that boat. I pulled a lot of great ideas from her - smaller version, but still...
Thanks again


What does OC stand for?

Deep Sea

OC Diver was the name of my charter boat. Had it for 20 years and use the name on any internet forum I'm on. OC is short for Ocean City, MD.

Ted
 
Ncheaven wrote;
“ Assuming you have an outboard already, going higher up hp might not get you much additional speed, so check your actual speed against calculated hull speed. ”

Yes but not so much.
Because of the very fine ends (bow especially) the sailboat hull will push the water aside late as in when the hull is further fwd. So the effective WLL will be shorter.

Sailboats do this because while under sail they are going considerably slower than hull speed so to optimize what they usually do .. go slow. At these well under hull speed speeds the sailboat maximizes their very low power (sails) most of the time. And at those speeds they will be very efficient.

And w a trawler or similar boat w full ends, it will respond to longer than measured WL lengths … and will be faster than using the traditional (actual) WLL.
 
We towed a small sailboat once at our normal tow speed, nearly capsized it.
Good advice to check if hull speed is reached before adding power.
 

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