Sailboat Conversion to Trawler

Sep 17, 2021
15
Cal 21 James River
I've just been reading some articles about converting my small sailboat to a Trawler. Does anyone have any information or experience with this project? Pictures and design ideas would be very helpful. Thanks
Deep Sea
 
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Mar 20, 2015
2,293
C&C 30 Mk1 Silver Harbour, Lake Winnipeg
Based on my professional experience in the automotive field, which is much more economical than the marine field, converting would likely be MUCH more expensive than simply buying the trawler you want.
(My lesser experience in the DIY marine field matches that)

If you are doing it for "fun", then cost and time doesn't matter obviously.

If course you could simply remove the mast.. seal the resulting deck holes and yer done.... But that doesn't seem like a trawler to me.

Edit: looking at your profile it seems you likely know what it may cost.. :waycool:
It all depends on what you want the boat to do. Actual trawling/fishing ? Just a low powered, economical boat ?
 
Last edited:
Oct 22, 2014
16,440
CAL 35 Cruiser moored EVERETT WA
converting my small sailboat to a Trawler.
Into a boat designed to trawl a fishing net? Or do you mean removing the mast and rigging, then powering the boat by electric or fossil fuel.

While I feel such an action might have “William Lapworth” turn over in his grave and unleash the demons from the under world, it is said that a sail boat hull is an efficient shape to cruise.

The 21 seems a bit small for such an investment. Then on the other hand folks soup up go carts to drive on the highway. Why not.

If your thinking “trawler for fishing” I think you might find the boat lacking in adequate space.

The retractable keel would help to provide stability to the boat. It’s retractable set up allows entry into shallow waters.

For sure it will be a path less traveled by most boat owners.
 
Oct 2, 2008
3,631
Pearson/ 530 Strafford, NH
It would change the stability of your boat. The mast does more than providing propulsion, do some research.
 
Sep 17, 2021
15
Cal 21 James River
I've done some reading on the ballast issues. My swing keel carries 360 pounds. I plan to compensate with adjusted ballast for stability. Possibly cut up my keel and add some concrete after I adjust the fore and aft positioning. Sound about right to you?

I'm retired as well. Loving life!
Deep Sea
 
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Sep 17, 2021
15
Cal 21 James River
Based on my professional experience in the automotive field, which is much more economical than the marine field, converting would likely be MUCH more expensive than simply buying the trawler you want.
(My lesser experience in the DIY marine field matches that)

If you are doing it for "fun", then cost and time doesn't matter obviously.

If course you could simply remove the mast.. seal the resulting deck holes and yer done.... But that doesn't seem like a trawler to me.

Edit: looking at your profile it seems you likely know what it may cost.. :waycool:
It all depends on what you want the boat to do. Actual trawling/fishing ? Just a low powered, economical boat ?

Looking for a low powered economical boat. I have the boat and it has a bad leak in the keel area. I gain about 5 to 10 gallons in a good sailing day. I love the boat but I don't like the leaks. I removed the keel and don't want the hassle of repair and replacement. 1st mate is not much for sailing but she likes to power through the water at a leisurely pace so it seems like a win, win. I plan a full conversion of the cabin and power plant. The hull will remain origional except for the engine accommodations.
Deep Sea
 
Sep 17, 2021
15
Cal 21 James River
Into a boat designed to trawl a fishing net? Or do you mean removing the mast and rigging, then powering the boat by electric or fossil fuel.

While I feel such an action might have “William Lapworth” turn over in his grave and unleash the demons from the under world, it is said that a sail boat hull is an efficient shape to cruise.

The 21 seems a bit small for such an investment. Then on the other hand folks soup up go carts to drive on the highway. Why not.

If your thinking “trawler for fishing” I think you might find the boat lacking in adequate space.

The retractable keel would help to provide stability to the boat. It’s retractable set up allows entry into shallow waters.

For sure it will be a path less traveled by most boat owners.

My most humble apologies to Mr. Lapworth but the 1st mate has over-riding authority :) I don't fish but we do like to cruise at a slow speed and sight-see, explore and enjoy the water.
Deep Sea
 

dLj

.
Mar 23, 2017
1,893
Belliure 41 Now on the Chesapeake
I always weigh how much I want to be on the water compared with how much time I want to work on a project. When I was younger I liked spending a fair amount of time on a boat project but as I get older I find I prefer to spend more of my time actually using the boat.

You must decide that balance for yourself. If I was in your situation, I would sell the sail boat and buy the preferred trawler. Much less time working on a project, more time enjoying the boating. But you may find a different project/boating balance.

dj
 
Sep 17, 2021
15
Cal 21 James River
No doubt I love being on "and in" the water. I'm a Navy bratt and a retired deep sea diver. Being retired I have more time for my hobbie which is building wooden boats. I'm currently in the middle of building the Seneca. One of Jeff Spira's little dorys. Working on the Trawler conversion in conjunction with my Seneca sounds like a great time.
Deep Sea
 
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Mar 20, 2015
2,293
C&C 30 Mk1 Silver Harbour, Lake Winnipeg
which is building wooden boats.
Hmm...sounds like a nice small wood trawler will happen one day.

A couple weeks ago I happened on a website of a guy who used to design some nice ones.. unfortunately he died recently nor can I remember his name.

As I admired them..A voice was saying... Great loop... Great looopppp.

A nice vintage looking "motor launch" maybe.. hehe.
 
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Oct 22, 2014
16,440
CAL 35 Cruiser moored EVERETT WA
Deepsea's envisioned trawler, might be a rather spartan Great Loop boat.
 

PaulK

.
Dec 1, 2009
862
Sabre 402 Southport, CT
I've done some reading on the ballast issues. My swing keel carries 360 pounds. I plan to compensate with adjusted ballast for stability. Possibly cut up my keel and add some concrete after I adjust the fore and aft positioning. Sound about right to you?

I'm retired as well. Loving life!
Deep Sea
Adding ballast may help, but it will be higher up than the swing keel was, so the boat will behave differently - likely rolling a lot with the canoe body the Cal21 has. Concrete is not actually all that dense as ballast. Getting it wet with salt water (inevitable) may cause it to disintegrate. Pump "sand" out of the bilge, and there goes your ballast. As All U Get mentioned, the mast also helps dampen rolling - much like the balancing stick that tightrope walkers use. Removing the ballast keel leaves you with nothing to keep you from going sideways in any wind. You will need to add some sort of keel structure as well as install an engine. The weight of the engine, fuel tank and battery(ies) will need to be placed carefully in such a small, light boat, Unless you get a sail drive, the hull's shape may prevent the propeller shaft from the most effective (horizontal) angle. If you enjoy building wooden boats, it might be quicker and cheaper to build something like one of Bolger's or Sam Devlin's designs. A big dory would have a hull more suitable for fitting out as a trawler than what you have.
 

Joe

.
Jun 1, 2004
7,510
Catalina 27 Mission Bay, San Diego
Not sure if you will find much help here.... since this forum is populated by sailors who are interested in sailing and talking about their sailboats. Over the past 20 years in this forum I've seen very few, (hmm, make that no), discussions on converting a small, swing keel, sailboat to a heavy, inboard powered trawler. I wish I could point you towards other like minded folks that could relate to your dream... but.. other than suggesting a search engine query for "sailboat to trawler conversions" I'm at a loss for helpful ideas. Good luck.
 
Jan 1, 2006
6,182
Slickcraft 26 Greenport, NY
Traveling at 5 knots can be very pleasant. When I see these boats with 4 outboards on the transom I wonder about what those travelers miss while screaming along.
But I wonder, why you don't just take the sails off. Or better yet create a "Riding sail" to dampen the rolling back and forth. Sailboat hulls aren't designed to be stable when flat. They will roll back and forth to an uncomfortable degree.
 
Feb 26, 2009
604
Oday 30 Anchor Yacht Club, Bristol PA
There are hundreds, thousands of trawlers out there begging to be saved just like sailboats needing to be saved why chop up a boat when you can get one for almost nothing,

just because you can doesn't mean you should destroy a boat to make it into something that was not meant to be, most wooden boat builders know that! Ok well I know it.lol
 
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Oct 22, 2014
16,440
CAL 35 Cruiser moored EVERETT WA
Joe you are correct. This idea is but a small fractional interest to the bulk of members here. There have been posts.

As in this one from 2010


As has been suggested. The hull shape of the Cal21 presents some compilations. I am less inclined to loose the iron keel and more inclined to repurpose it as a fixed keel hanging below the hull in a horizontal fashion. Provides a long keel to the boat. Sacrifices only a foot or so in added draft and places the weight in the boat where it is needed for stability.

As has been suggested there maybe better hull designs for this project. The MacGregor’s come to mind.
 
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Feb 26, 2004
22,024
Catalina 34 224 Maple Bay, BC, Canada
just because you can doesn't mean you should destroy a boat to make it into something that was not meant to be,
Well put.

Look, OP, a few have suggested you look into the dynamics of removing a mast from a hull designed as a sailboat.
Not only are they well meant points, they are actually critical to the operation of the boat.
It would change the stability of your boat. The mast does more than providing propulsion, do some research.
You are wrong to be thinking only about the keel and ballast.
Could be, too, dead wrong. literally.
 

walt

.
Jun 1, 2007
3,455
Macgregor 26S Hobie TI Ridgway Colorado
Retired.. go for it. You will have a lot of fun and probably end up gaining a fair amount of knowledge. My only advice is that if you ever decide you no longer want this boat with major modifications, its resale value is likely going to be the same as scrap or parting out. On the other hand, the bad leak in the keel area might have the same effect on resale. If the fun and satisfaction you will have are worth the cost of the boat, have at it. Who knows, the satisfaction of a project like that (which not everyone will get) may far outweigh the $$ cost.
 
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