Want to build a dinghy, easy towing is priority..recommendations?

[preserved_killick]

I currently have a 10 foot fiberglass Puffin Dinghy that I tow behind my 30 foot sailboat when cruising. http://frankfortboatworks.com/Specs.html

I find the Puffin to be very stable, rows pretty well and certainly is durable. However, when towing, at 5kts or more she digs her stern, lifts her bow and really adds drag. I'm not sure what to attribute this to, possibly simply her short length..though you would think the hull would plane.

I've wanted to build a dinghy for some time, but can't decide on the design. I will be primarily using this as a tender as transport to my boat's mooring and will drag it along on cruises. Towing well is a priority.

Needs/wants in order:

1. Tow well
2. Pretty to look at
3. Stability, will rig to sail
4. Storage to get stuff to boat

Any suggestions on what makes for a good towing dinghy?

At this point, I'm attracted to double ended peapods, and would likely build as glued plywood shiplap.

Any suggestions, voices of experience??

Thanks

PK

[Gopez]

Doug Hylan's Beach Pea
http://www.dhylanboats.com/beachpea_plans.htm
http://www.grapeviewpointboatworks.com/peapod.html

[preserved_killick]

I like the looks of that D.N. Hylan Peapod. Anyone familiar with how a hull shape like this tows behind a boat?

[Dave Lesser]

Anyone familiar with how a hull shape like this tows behind a boat?

Great!
Also important, rows well.

[Full Tilt]

My double ender doesn't tow worth a d..n. She wil surf ahead to port and starboard in following seas and if the painter is short can even ram the stern of the boat towing it. Flat bottoms and transomed dinghys tow better. The suction created by a transom keeps the dinghy well back and the flat bottom lifts her up a little for less drag. Unfortunately this shape isn't ideal for sailing or rowing performance.
If you must tow a double ender, installing a bucket on the tow line a fathom ahead of the dinghy with the mouth facing forward stops the vessel surging ahead on following seas.
Mike

[johnw]

Towing and rowing well were considerations when I designed the boat I'm now building, Meerkat. I think to tow straight, it's a big help to have a skeg, and to tow light, you need a flat enough run to allow the empty boat to plane. That's all easier to do with a transom hull, but if it is a veed transom with a short, steep run, it won't tow worth a damn. An El Toto, for example, doesn't want to plane, so it tows heavy, whereas a 12' aluminum fishing boat tows light, but lacking a skeg, hunts all over the place.

[Daniel Noyes]

My double ender doesn't tow worth a d..n. She wil surf ahead to port and starboard in following seas and if the painter is short can even ram the stern of the boat towing it. Flat bottoms and transomed dinghys tow better. The suction created by a transom keeps the dinghy well back and the flat bottom lifts her up a little for less drag. Unfortunately this shape isn't ideal for sailing or rowing performance.
If you must tow a double ender, installing a bucket on the tow line a fathom ahead of the dinghy with the mouth facing forward stops the vessel surging ahead on following seas.
Mike

+1
the point of a draggy rocker bottom dinghy, besides being short is a high drag hull so it has trouble surfing up on your big boat in waves or when you are motoring and slowing down.

Having said that, Banks type dories have been popular dinghies with the Gloucester Schooners for generations.

[Thad]

Capacity of tender and type/size boat towing are considerations. I've towed the Columbia model dinghy (which many a glued lap design imitates) and it is very good (11.5') but I also have towed the 8' tender for 8 meter of Starling Burgess (designed to tow, having a bronze strap towing eye at the bottom of the stem), an excellent towing tender in that size. The plans are at Mystic in the set for the 1925 8 meter. As the plan is lines with few details, double chine, it could be built in plywood.

[preserved_killick]

Thanks Guys, this all good info. I hate to admit it, but the more I look at the peapods the more I'm willing to ignore their shortcomings.

Question: why would my 8'6" Puffin dinghy dig her transom in while under tow? She tracks well (has a little skeg) but at 5kts the bow comes up, and the stern tries to dig in. She's a sea- anchor at 5 + ?

PK

[johnw]

Thanks Guys, this all good info. I hate to admit it, but the more I look at the peapods the more I'm willing to ignore their shortcomings.

Question: why would my 8'6" Puffin dinghy dig her transom in while under tow? She tracks well (has a little skeg) but at 5kts the bow comes up, and the stern tries to dig in. She's a sea- anchor at 5 + ?

PK

Same reason an El Toro does. Too much rocker an vee aft, which keeps the boat from planing. You need something with a flat enough run aft to come up out of the hole, or you're fighting the hull speed of the dinghy.

By the way, I've sailed the Beach Pea, and found it too light and squirly. If a boat is going to be that light, it needs firmer bilges. I don't doubt it rows well, though.

[preserved_killick]

Same reason an El Toro does. Too much rocker an vee aft, which keeps the boat from planing. You need something with a flat enough run aft to come up out of the hole, or you're fighting the hull speed of the dinghy.

That makes sense. I bet a flat plywood bottom skiff skeg tows well. I need to enjoy looking at whatever I build though.

[johnw]

That makes sense. I bet a flat plywood bottom skiff skeg tows well. I need to enjoy looking at whatever I build though.

Post #8 looks good.

I guess there are two things you need to have the boat plane when you tow it. A bottom that is flat enough that the deflection angle isn't too great, and a run that's straight enough for the water to release at the stern instead of being sucked up. This probably means a bit more wetted surface aft than is optimum for a rowing boat, which is likely why your present boat has the stern it does. It's also hard to combine that straight run with a boat that can carry some weight and still row well. More rocker makes it harder for the boat to plane.

[Dave Lesser]

The Beach Pea has a flat bottom without any rocker.
Some other recent discussion of the Beach Pea Here: http://forum.woodenboat.com/showthread.php?142036

[John B]

Is that Puffin an Oughtred design? They're pretty good from what I've seen.... Good compromise of weight and shape so as to be a optimal tender for towing and rowing.
I've towed and measured drag on various dinghies over the decades. Far and away the worst towing boat I've had and still have is our little sabot pram for just the reasons you describe. The best is our 15 ft stripper, but the challenge is slowing it down in a gale. I use 2 painters to the quarters and throw a drogue out behind it when its very fresh. I did have plastic funnels on the painters and that seemed to help. ...as the boat surfs up the slack painter reverses and submerges the funnell, which brakes the boat some.... and I throw the solar showers in the boat as well for some weight. We had a scary day where she looked like flipping on the crests as the wind hit it on a beam reach.

Oh , and I mess around with painter lengths quite a bit to try find an optimal place for the dingy on the wave.

[Wooden Boat Fittings]

PK -- How far down the Puffin's stem is the towing eye? It might be worthwhile experimenting a bit with its height before you discard the dinghy altogether.

[johnw]

I'm not finding any good pictures of the 10' puffin's stern, but here's the 8' puffin:


Looks like it has a short, steep run. If the 10' version is like that, it could be the problem.

[gilberj]

I know several people who have used traditional clinker rowing boats as tenders. I have seen these trip on the sharp stem and dig in enough that in a rough sea the dipped the side and started to fill. I like a pram, preferably with a V bottom. These boats develope a stability when they are being towed fast. In my experience flat bottomed boats are not quite as good, and round bottom boats do not get the chine effect. Some effort in the design stage to leave a clean wake when rowing, but provide enough buoyancy to reduce squat when towing fast. My Father and I drew up an 8 foot clinker pram for him to build. The midship bilges were pretty firm giving good stability, and the transom aft was quite deep and had a fairly steep rise of floor. It was a unqualified success. It rowed easily with astonishing carry, and it towed straight and true, and was lighter (towing) than out previous smaller lighter weight pram.
Having said all that My son and I are very slowly building Reuel Parker's Periagua 14' pram. My son is about 2 hours drive away and has a life of his own. At this time I could not face a full clinker build, even with glued laps, I have very little time, to spare and when I do I prefer sailing to building.

[preserved_killick]

PK -- How far down the Puffin's stem is the towing eye? It might be worthwhile experimenting a bit with its height before you discard the dinghy altogether.

The towing eye is high, just under the point of the bow:



I've experimented with short to super long painter with no difference. I've not tried adding any weight. I wonder if a gallon of water in the bow would help?

I would like to get this to tow better, but I'll likely build a dinghy anyway!

pk

[johngsandusky]

I keep 3 gallons of water in my dinghy for trimming and stability. I push them aft when towing to prevent her vertical bow transom from throwing spray inboard. Try ballast, you'll need to secure it somehow.

[Roger Long]

I'm quite happy with the way my 8'-6' Puffin tows. It does squat but I've towed it through some very ugly stuff (over 6200 nm) and never worried about it joining me in the cockpit or flipping.

The two models are both outside Hamilton Marine in Portland and the 10 footer has a much flatter run. It appears to be optimized for planing with an outboard motor.

I think some tuck in the run to pull the stern down is an essential feature for good towing in rough water.

[Dave Lesser]

Scanned from the 2005 Calendar of Wooden Boats. The one in the center is by Jimmy Steele, the other two are Beach Peas. Note how high the bows ride, even with the towing eye high on the stem. Can't tell if they're using any ballast. Photo by Benjamin Mendlowitz



Commentary by Maynard Bray

[preserved_killick]

I'm quite happy with the way my 8'-6' Puffin tows. It does squat but I've towed it through some very ugly stuff (over 6200 nm) and never worried about it joining me in the cockpit or flipping.

The two models are both outside Hamilton Marine in Portland and the 10 footer has a much flatter run. It appears to be optimized for planing with an outboard motor.

I think some tuck in the run to pull the stern down is an essential feature for good towing in rough water.

Thanks Rodger, I have no complaints at all as far as stability. The Puffin is indeed very stable in all conditions. I'd just like to reduce the drag...and may be asking for too much.

[Roger Long]

The Puffin is indeed very stable in all conditions.

Here's a picture of the Puffin towing at a bit over 6 knots.



The trim angle looks extreme but I've seen plenty of dinghies planing under sail with this kind of trim angle as well as outboard boats. I can pull the painter up short at this speed, it's a bit of work but it can be done. You can feel a significant difference in drag as you pull the dinghy to different places on the stern waves. I lose about 1/4 knot towing the dinghy at this speed. It's not significantly different from this flatter run dinghy I used to have.

[John B]

There seems to be 2 schools of thought emerging. One is get a dinghy with the least drag and least impact on your mothership performance, the other is to get one that does drag so that it never rides up on the transom( in a seaway running). I prefer the first approach myself, you can always ballast up or as I said earlier make other arrangements.

This is one way of ballasting your dinghy and quietening down your boat at the same time.


..

[Tom3]

I currently have a 10 foot fiberglass Puffin Dinghy that I tow behind my 30 foot sailboat when cruising. http://frankfortboatworks.com/Specs.html
I will be primarily using this as a tender as transport to my boat's mooring and will drag it along on cruises. Towing well is a priority.

Needs/wants in order:

1. Tow well
2. Pretty to look at
3. Stability, will rig to sail
4. Storage to get stuff to boat

Any suggestions on what makes for a good towing dinghy?

At this point, I'm attracted to double ended peapods, and would likely build as glued plywood shiplap.

Any suggestions, voices of experience??

Thanks

PK

I'll put in my 2 cents because you twice mentioned, tows well.

I don't think there is a tender that tows as well as a pram. I've towed prams up and down the east coast from Canada to the Exumas, twice. I've yet to have a problem that couldn't be dealt with underway, now nearly 3 decades of pram towing.

If a tender is low in the stern, squirrelly in following seas, or otherwise unmanageable under tow, it's not as good as a well designed pram for towing.

I think Joel White designed the Nutshell pram with towing in mind. And it's second best quality is hauling big loads to the boat. It will never row as well as a longer Peapod, sail as well as any longer vee bowed tender(our Nutshells is enjoyabe for both, if not overloaded-very stiff under sail), but if towing is your first priority, here's the typical performance of a 9'6" Nutshell pram behind our yawl in 30-35 knots, downwind. The tender should plane just like the mothership.

[preserved_killick]

Rodger, that looks just like my dinghy! Tom3, fantastic photo! There's just something about prams that just don't look quite right to me, useful as they are. Is that your boat? If my boat looked that good I wouldn't care what my dinghy looked like!

[John B]

Nutshells are pretty light , flat in the run and have that neat little 'planing strake' bottom. Does it run up on you Tom?

[Roger Long]

Is that your boat?

Yes.

http://forums.sbo.sailboatowners.com...play.php?f=142

[Tom3]

Rodger, that looks just like my dinghy! Tom3, fantastic photo! There's just something about prams that just don't look quite right to me, useful as they are. Is that your boat? If my boat looked that good I wouldn't care what my dinghy looked like!

Then I misunderstood your towing priority. If it's simply drag and not heavy weather, a well designed Pea pod, Whites Shellback and many other great performance(under oar or sail)
dinghys would fit the bill and are much prettier.

Our Nutshell slides along on very little water while under tow.

Just be careful towing in tough conditions, problems can crop up quickly towing many tenders.

[Tom3]

Nutshells are pretty light , flat in the run and have that neat little 'planing strake' bottom. Does it run up on you Tom?

It sure does under the right conditions. We're coastal sailors that will overnight occasionally so I can get accurate weather forecasts for our time frame.

The usual fix is a bowline connection to the painters loop(we never loose the dinghy with a loop on the end). That gives you more length to adjust and creates the drag it needs as it slackens in following seas.

[Roger Long]

It sure does under the right conditions. We're coastal sailors ....

I'm a coastal sailor as well, anchoring nearly every night and always tow my dinghy (6200 nm so far this year) . The times I've gotten caught have almost always come up so quickly that the last thing I would want to be doing is fooling around singlehanded trying to get the dinghy alongside to add a drogue or weight. Dinghy threatening conditions are usually a combination of wind, tidal action, and shallow water. They usually can be foreseen but I would find myself rigging for hard towing many times that it wasn't necessary. It would only take not doing it once in the wrong conditions to loose the dinghy or have it crash into my wind vane.

My dinghy costs me less than a quarter knot towing at maximum speed and less at normal cruise. An easier towing dinghy might cut that in half but it's worth it to me not to have to worry about what's going on behind me in one of the nasty spots I encounter often.

[Tom3]

I'm a coastal sailor as well, anchoring nearly every night and always tow my dinghy (6200 nm so far this year) . The times I've gotten caught have almost always come up so quickly that the last thing I would want to be doing is fooling around singlehanded trying to get the dinghy alongside to add a drogue or weight. Dinghy threatening conditions are usually a combination of wind, tidal action, and shallow water. They usually can be foreseen but I would find myself rigging for hard towing many times that it wasn't necessary. It would only take not doing it once in the wrong conditions to loose the dinghy or have it crash into my wind vane.

My dinghy costs me less than a quarter knot towing at maximum speed and less at normal cruise. An easier towing dinghy might cut that in half but it's worth it to me not to have to worry about what's going on behind me in one of the nasty spots I encounter often.

True enough and I followed your travels so you have good experience with your dinghy.

Our first pram was 8' and worked well for a decade. Then we raised two kids in the last 20 years in our current 9'6" Nutshell which has handled the added load well.

It's a small but able "boat", the minimum for safely sailing or transporting 4 with gear we find. I built it when my son was born, he's now 20. These days, with our 2 in college, my wife and I have dinghy to spare.

Only twice in 3 decades of pram towing have I had to get into the boat. Each time was to bail it, once a deluge while sailing off Florida, another when the centerboard plug loosened on our present Nutshell.

There have been a few episodes when the pram came knocking on the stern, that had to be addressed by lengthening the tether.

These days our only off shore sailing of any length is overnight across the Gulf of Maine to the Cape. We do that quite a bit and sail that area for a couple weeks.

I'm a stickler for light air sailing(I have a passion for it with our old boat), so I wouldn't be happy with any more drag than our dinghy gives, so I fall in the "planing" group.

As I trim sails aft, the last "sheet" is the dinghy tether which I trim to get her on her lines and coasting pretty well on the stern wave, with minimal drag.

[Roger Long]

so I fall in the "planing" group.

I'm not sure mine isn't planing. At a S/L ratio of 2.3, it's in the planing regime and it isn't sucking itself under. I've seen plenty of sailing dinghies with a similar hull shape plane under sail. At light air speeds, the Puffin has a pretty easy moving hull shape. It's certainly easier to row than my older dinghy seen above.

[rbgarr]

Another consideration when towing is to set the painter at a length so the tender is on the downhill slope of your wake. It takes some of the drag off and it can ride better. Towing it about three quarters of your waterline length aft would put it in a sweet spot in most conditions. Further aft if your moving at hull speed. A stout length of bungee tied into a sagging section of the painter can alleviate tugging when it's brought up short, too.

[Jay Greer]

I have always preferred to tow a dinghy off the quarter. On a ketch this is usually a point off of the mizzen shouds on the lee side if we are taking a long board. The boat will then ride comfortably on the quarter wave once the length of the tow line is adjusted. And, there is less tendancy for the tender to charge around. The boat in tow actually has the least amount of drag at this point.
Jay

[djmeaney]

I was recently looking for an 'explore dinghy' for my 19' O'Day Mariner. After a lot of searching I decided on the Spindrift by B and B Yacht Designs. I have the plans, but have not started building yet -- so I have no first hand knowledge of the build or performance. Here's the link to B and B if you like to check it out: http://www.bandbyachtdesigns.com/yachtt3.htm

Dan

[johnw]

I'm a coastal sailor as well, anchoring nearly every night and always tow my dinghy (6200 nm so far this year) . The times I've gotten caught have almost always come up so quickly that the last thing I would want to be doing is fooling around singlehanded trying to get the dinghy alongside to add a drogue or weight. Dinghy threatening conditions are usually a combination of wind, tidal action, and shallow water. They usually can be foreseen but I would find myself rigging for hard towing many times that it wasn't necessary. It would only take not doing it once in the wrong conditions to loose the dinghy or have it crash into my wind vane.

My dinghy costs me less than a quarter knot towing at maximum speed and less at normal cruise. An easier towing dinghy might cut that in half but it's worth it to me not to have to worry about what's going on behind me in one of the nasty spots I encounter often.

I wonder, would it work to have a line attached to the stern of the dinghy that you brought aboard, and could throw out a drogue attached to that line when things got rough? That way you wouldn't have to have the extra drag unless you needed it.

[Roger Long]

I wonder, would it work to have a line attached to the stern of the dinghy that you brought aboard, and could throw out a drogue attached to that line when things got rough? That way you wouldn't have to have the extra drag unless you needed it.

Maybe. I would have to see some numbers from tests though to convince me that the Puffin is a hard towing dinghy. As a boat designer, I think it has quite a nice shape. It's a bit on the heavy side but there have been plenty of times when I appreciated this:

[Willin']

If you don't care for the Nutshell's pram bow, the Shellback makes it a pretty pointy ender. Same good towing characteristics, large capacity, easy pulling and fun to sail, but it will squat at higher speeds.



Here I have it on a short lead, but the nose comes down a bit if I let it out to surf the wake.

I've never had issues with it at sailing speeds, but behind my skiff at 10 kts or greater it reaches for the sky and fills with water even when the slot is filled.

I love mine and will probably build another if this one ever starts to degrade seriously, which at 15 years is just now starting to happen.

ETA after reading the following post, the shellback rows 4 adults easily and I've seen 6 in one. The downside is, at 11'+ it needs a large deckspace or substantial davit to bring it aboard.

[cybuilder]

Whatever tender you decide to build, make sure it's big enough for your crew. I built the 7'7" Nutshell years ago and still kick myself for not building the 9'6". Disturbingly little freeboard with two adults and gear.

[Tom3]

If you don't care for the Nutshell's pram bow, the Shellback makes it a pretty pointy ender. Same good towing characteristics, large capacity, easy pulling and fun to sail, but it will squat at higher speeds.



Here I have it on a short lead, but the nose comes down a bit if I let it out to surf the wake.

I've never had issues with it at sailing speeds, but behind my skiff at 10 kts or greater it reaches for the sky and fills with water even when the slot is filled.

I love mine and will probably build another if this one ever starts to degrade seriously, which at 15 years is just now starting to happen.

ETA after reading the following post, the shellback rows 4 adults easily and I've seen 6 in one. The downside is, at 11'+ it needs a large deckspace or substantial davit to bring it aboard.

I considered building a Shellback years after building the Nutshell. It's a better performer under oar or sail. It's has a more slender shape at the WL that gives it a better glide and track than the 9'6" Nutshell. But it's just a bit more tender due to that. Plus the Nutshell bow works well for our bow in situation at our dinghy dock. I'd still love the performance, I'd consider keeping one of each!

You mentioned degrading. I'm curious what you mean. I scrimped on materials building the Nutshell and used Marine grade AC fir instead of a better quality finish material. It's held up well with 20 seasons of use/abuse. Dragging miles over rock beaches, I've worn the bronze shoe off the bow and a good portion of the oak keel. The fir will never have a "yacht" finish, and I store the Nutshell outside, year round.

The biggest problem has been failure of the epoxy joint between the bottom and garboard planks just forward of the midship laminated frame.

I thought this may have had something to do with the fir(I was sure to well fill the grain and joint at build), but I've seen the same failure with better plywood as well. This failure could also be due to the severe stresses the sail rig twists into this joint.

I've made repairs to each side in this area, perhaps twice on one side. I went at them aggressively, knocking off a new flat with a plane, and epoxied on a long plywood patch, then faired them back into the joints shape.

That has solved the problem, so far. All other areas seem to be more than up to it.

[Tom3]

Whatever tender you decide to build, make sure it's big enough for your crew.

Isn't that the truth. They all have their load limits, dinghys, and when you reach that limit, it's "nobody moves, nobody gets hurt".

[Willin']

I used 1080 okoume on mine, didn't scrimp on anything but the paint, which is an industrial oil based coating no longer available that brushed out nicely with enough Penetrol. I've had the bottom/garboard seam just aft of the midships frame not exactly open but become noticeable at about 10 years of use. It never leaked nor showed any ply delam so I just sanded and reefed it out, soaked it in penetrating epoxy and faired it with West System. It's still visible but not getting any worse.

The main concern is matching port and starboard circular stress cracks that are becoming worse. They look almost like targets in the middle of the bottom strake both aft of the center thwart and forward of the trunk. We typically row with me in the bow and wifey on the stern thwart (we're both pretty large folk) which I'm guessing puts a lot of beam end type stress on the middle of the boat. I gave them the same treatment as the seam but they came back after one season, so I reckon it's the beginning of the end.

Fortunately, I saved the molds and patterns, so building a new one shouldn't be a big deal.

I considered building a Shellback years after building the Nutshell. It's a better performer under oar or sail. It's has a more slender shape at the WL that gives it a better glide and track than the 9'6" Nutshell. But it's just a bit more tender due to that. Plus the Nutshell bow works well for our bow in situation at our dinghy dock. I'd still love the performance, I'd consider keeping one of each!

You mentioned degrading. I'm curious what you mean. I scrimped on materials building the Nutshell and used Marine grade AC fir instead of a better quality finish material. It's held up well with 20 seasons of use/abuse. Dragging miles over rock beaches, I've worn the bronze shoe off the bow and a good portion of the oak keel. The fir will never have a "yacht" finish, and I store the Nutshell outside, year round.

The biggest problem has been failure of the epoxy joint between the bottom and garboard planks just forward of the midship laminated frame.

I thought this may have had something to do with the fir(I was sure to well fill the grain and joint at build), but I've seen the same failure with better plywood as well. This failure could also be due to the severe stresses the sail rig twists into this joint.

I've made repairs to each side in this area, perhaps twice on one side. I went at them aggressively, knocking off a new flat with a plane, and epoxied on a long plywood patch, then faired them back into the joints shape.

That has solved the problem, so far. All other areas seem to be more than up to it.

[rbgarr]

The hull of a small multi-purpose dinghy twisting under sail (and cracking) is a thought that hadn't registered with me as a potential problem. Duh.
The dagger/cb box strains had been the one I'd thought more about.
Thanks for mentioning it. If I alter my rowboat for sailing it will be something to take into account

[KimB]

There is a very nice nesting dinghy kit that has just shown up on the market by PTwatercraft in Port Townsend, WA. They tow very well but they also nest together in a very small package for deck storage.

There was one at the Bob Perry Rendezvous yesterday and it attracted quite a crowd because it has to be the nicest nester I have ever seen. (It also has an optional carbon sailing rig.) It was designed and is offered by Russell Brown who is quite an accomplished boat guy (see the recent article about him in Professional Boatbuilding magazine.)

You can see all sorts of details about it on his website which is: http://ptwatercraft.com/ptwatercraft/Welcome.html

I have used him for several projects and he is a super nice guy and very easy to deal with. So I guess you could say I am a happy customer of Russell's.

Kim Bottles - Blakely Harbor, WA

Ps. Bob Perry likes it so well that he plans to review it for Sailing Magazine.

[John B]

Thats a neat boat all right.

The puffin of Rogers is pretty well a good wholesome general tender as far as I can see, nice shape. But for PK ,a 10 ft glass dinghy is a big unit to tow with a 30 footer. Maybe the drag issue is just down to size and weight. We towed a glass 10 foot tender for years when the kids were little, and even though its a good shape it weighed near to 60 kg, too much for its length really.

Narrow waterline boats ( unloaded) tow really well, the shellback looks good, But the tradeoff is they tend to be a bit flicky getting in and out. The stripper is like that but its amazing how quick you become accustomed to it. Its also amazing how alert people become when they get in it.

..