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Depth finder for 27-foot sailboat


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My H-Boat has a rudimentary 12v electrical system. I'm adding a LI power station. The maximum output is 200w. I'm considering adding a depth finder. I do not want to make a hole in the hull, and I would probably mount the display on a swing out arm rather than mount it on the cockpit bulk head. Hell, it's be nice to have it displayed on my smart phone. I'd like to minimize wiring too.

I think my hull is solid fiberglass, so a glue-in transducer should work. Here's what the surveyor said: 

"The hull showed solid fiberglass reinforced plastic (FRP) from a female mold utilizing woven roving and stranded mat. The decks showed FRP core construction from a female mold utilizing similar materials. Coring material type was not ultimately confirmed but some available literature referred to balsa."

Finally, I don't want to spend a lot on it. I wouldn't have it on all the time.

I am a dumb-fuck on most technical things, so I welcome your suggestions.

Thank you.

B.C.

 

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1 hour ago, Bull City said:

I welcome your suggestions.

The wireless part might interfere with the inexpensive part.

That said, there are a number of wired shoot-through-the-hull types for around US $100.

I liked the Norcross on my old Mac25. Has a skinny-water alarm. Plenty more where that came from.

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Hey Bull

Do you really need it where you sail? My boat drafts 1,5 m, which is a bit more than yours, and I do fine without a depth finder, even though I'm mostly sailing in a shallow fjord. I only have a compass and a speed log onboard, though I could use the depth finder when anchoring. If it's for anchoring, you can get a handheld depth finder, which should be fine.

I do hit the bottom from time to time, but that's probably because I'm either tacking too close to shore or try to take "shortcuts" (read: shortcuts doesn't always save me time, especially when I run aground).

Keep us updated on what you end up with.

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3 hours ago, Zonker said:

I've used a cheap Garmin fishfinder round the world and was very happy with it. Glued the transom mount transducer to the hull and it read to > 600'. Cost about $75

Did you glue it to the transom, or to the inside of the hull? There's quite a difference. The first being a total fashion faux pas in my book, regarded by me as on the same level as stern archs.

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Glued inside the hull as the good book says

Book of Armaments, Chapter 2, Verses 9-21 

"And Saint Attila raised the hand grenade up on high, saying, "O Lord, bless this Thy hand grenade that with it Thou mayest blow Thine enemies to tiny bits, in Thy mercy." And the Lord did grin and the people did feast upon the lambs and sloths and carp and anchovies and orangutans and breakfast cereals, and fruit bats and large ..."

Oops. Wrong verse.

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13 hours ago, Misbehavin' said:

Hey Bull

Do you really need it where you sail? My boat drafts 1,5 m, which is a bit more than yours, and I do fine without a depth finder, even though I'm mostly sailing in a shallow fjord. I only have a compass and a speed log onboard, though I could use the depth finder when anchoring. If it's for anchoring, you can get a handheld depth finder, which should be fine.

I do hit the bottom from time to time, but that's probably because I'm either tacking too close to shore or try to take "shortcuts" (read: shortcuts doesn't always save me time, especially when I run aground).

Keep us updated on what you end up with.

Misbehavin', this makes sense. I was kind of excited because I just added my LI power station. I'll think about the hand held type.

2 hours ago, Zonker said:

Book of Armaments,

To quote again from the Book, "Brother Maynard, bring up the Holy Hand Grenade, I mean the Holy Hand Held Depth Finder!"

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3 hours ago, Zonker said:

Glued inside the hull as the good book says

Book of Armaments, Chapter 2, Verses 9-21 

"And Saint Attila raised the hand grenade up on high, saying, "O Lord, bless this Thy hand grenade that with it Thou mayest blow Thine enemies to tiny bits, in Thy mercy." And the Lord did grin and the people did feast upon the lambs and sloths and carp and anchovies and orangutans and breakfast cereals, and fruit bats and large ..."

Oops. Wrong verse.

... large bat transmitted coronavirus infected pangolins, by any chance?

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28 minutes ago, Bull City said:

Misbehavin', this makes sense. I was kind of excited because I just added my LI power station. I'll think about the hand held type.

I forgot to say, the handheld depth finders seem to only be about 200 USD.

I would actually like one myself, I'm just too cheap to buy one, having bought a new outboard bracket on monday, a MPPT and this https://www.sunbeamsystem.com/en/new-tough-with-double-uv-protection/ on tuesday as well as a new to me cradle today. Also looking at a brand new never used jib and main, which are for sale.

Please put up a review if you buy one, so you spare me buying the wrong one, I have already spent too much this week. TYVM in advance.

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1 hour ago, Misbehavin' said:

I forgot to say, the handheld depth finders seem to only be about 200 USD.

I would actually like one myself, I'm just too cheap to buy one, having bought a new outboard bracket on monday, a MPPT and this https://www.sunbeamsystem.com/en/new-tough-with-double-uv-protection/ on tuesday as well as a new to me cradle today. Also looking at a brand new never used jib and main, which are for sale.

Please put up a review if you buy one, so you spare me buying the wrong one, I have already spent too much this week. TYVM in advance.

Good on you for stimulating the economy. It's nice that you can walk on the solar panel in high heels. I'm sure that's why you selected it. :P  I forgot what kind of boat you have. Can you remind me? Or maybe I never knew.

I'll definitely report on a depth finder, if I get one.

Cheers.

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6 hours ago, Bull City said:

Good on you for stimulating the economy. It's nice that you can walk on the solar panel in high heels. I'm sure that's why you selected it. :P  I forgot what kind of boat you have. Can you remind me? Or maybe I never knew.

I'll definitely report on a depth finder, if I get one.

Cheers.

International 806, with the number referring to the length in cm. 1974/5 design by swede Pelle Petterson, actually as a bit newer alternative to exactly your boat. Was built without a care to racing rules, which makes it a very sympathic and balanced boat no matter the weather or point of sail. About 600 built.

Similar keel weight to yours, but with a deeper flared fin keel and about 200 kgs heavier in total overall, bit More rounded bottom with less longitudinal rocker though, which make it surf quite. well. Almost similar sail area with the jib and main, though the 806 class rules also allow a big overlapping 155% genoa, good for sub 15-knots winds and a big-ish 46 m2 (495 sqft) spinnaker.

IMG_3549.thumb.JPG.5fb7a4d3f399e2f6388a2f4cb44c73b1.JPG

Don't mind the IMOCA-style boom angle, I should have released the topping lift.

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Just to correct myself, probably a bit less than 600 built as I had forgot about this 2006 built, hull no. 521 for sale: https://kronborgmarine.dk/boat/int-806-nr-521/?utm_source=dba.dk&utm_medium=Admanager&utm_campaign=DBA

Very very nice, but ridiculously expensive, 295.000 DKK equaling about 43.000 USD. Mine was one tenth of that, although I've probably spent the same amount I bought it for, or double that on projects. I've written down all expenditures, but not totalled them.

I think most of them were built from 1975 'till the mid-80's. The first couple of boats (maybe only hull no. 1)  were buillt by Monark in Sweden, after that they were built in Denmark. Mine being a danish built 1976 boat, hull no. 174. After that, the plugs ended up at Ott Yacht in Germany, which also builds brand new Aphrodite 101 and H-Boats to order.

Edit: Just realised that I've painted double dark blue hull stripes in the same way as on the boat for sale, the difference being mine not having a stripe of exposed gelcoat between the lower stripe and bottom paint.

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About 10 years ago when I bought my Cal 22 for local lake sailing, my father in law purchased me a fish finder for my birthday.  On drive home, fish finder in hand, I said to wifey, "what the hell am I going to do with this...its not a fishing boat".  Noticed it had depth display, so I took it down to the boat wired it up and sat the puck on the hull (inside).   I'll be damned, it shows depth perfectly and as an anchoring bonus you can see the bottom terrain.  Mounted puck slightly facing forward in bow with a toilet wax ring.  Mounted fish finder so it swivels into companion way using ram mounts.  Been there ever since.  Works great. Also monitors the battery.  Couldn't have been much more than $100.  It was dumb luck on his part, but turned out to be the second best thing he has given me.  I should probably apologize.

 

IMG_4349.JPG

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14 hours ago, Misbehavin' said:

International 806,

Very nice looking boat. I imagine they have H-Boats for lunch. Does it have a PHRF rating?

BTW, where in Denmark are you located?

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4 hours ago, Notquitecapnron said:

About 10 years ago when I bought my Cal 22 for local lake sailing, my father in law purchased me a fish finder for my birthday.  On drive home, fish finder in hand, I said to wifey, "what the hell am I going to do with this...its not a fishing boat".  Noticed it had depth display, so I took it down to the boat wired it up and sat the puck on the hull (inside).   I'll be damned, it shows depth perfectly and as an anchoring bonus you can see the bottom terrain.  Mounted puck slightly facing forward in bow with a toilet wax ring.  Mounted fish finder so it swivels into companion way using ram mounts.  Been there ever since.  Works great. Also monitors the battery.  Couldn't have been much more than $100.  It was dumb luck on his part, but turned out to be the second best thing he has given me.  I should probably apologize.

 

IMG_4349.JPG

Thanks, Notquite. I'll take a look at these. After you started using it, did you ever get an urge to put a 150 HP outboard on your boat and scream around the lake looking for little fish? :P

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On the original topic.

I would suggest the Raymarine i40 setup.  I have the older ST40 which is essentially identical.  They are inexpensive, and you can get the "transom mount" transducer and set it up to shoot through the hull using a suitable adhesive or making a little tank for it or whatever.  They draw around 30 mA so you can run them all day and your batteries won't know the difference.  These just give you depth.  They are not a fishfinder.

There are also versions that also have speed and temperature transducers (which require drilling a hole in the hull), or wind transducers, if you want that.  However configured, they are good basic instruments that do not have the cost and complexity of a chartplotter installation with NMEA2000.

You can also get a Vexilar Sonarphone SP 200, which costs about the same and connects to your smartphone via bluetooth.  I have one of these also, though mine is the battery-powered version with suction cups, for use on canoes and other people's boats.  This will give you a fishfinder display on your smartphone, and integrate with Navionics and so on.  The disadvantage is you need a phone to make it useful and that can be a drawback when sailing all day in bright sun.

 

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11 hours ago, Bull City said:

Very nice looking boat. I imagine they have H-Boats for lunch. Does it have a PHRF rating?

BTW, where in Denmark are you located?

Roskilde fjord, west of Copenhagen, which splits Zeeland almost halfways from the northern coast of itself.


Our handicapping system for the last decades have been DH (Danish Handicap), which such as ORC is a mathematical VPP-based calculation based on measurements taken on the individual boat, but obviously adapted to Denmark and our predominant type of boats. PHRF/yardstick racing/rating went out of favour many years ago, but is still used in "regattas" with a more social scope, if you get what I mean.

Here's the measurement certificates for a H-boat and an Int. 806. I've inserted the "calculated values" for comparable sailing times in sec/nautical mile below, with regards to the type af sailing course, as it can't perform the calculations via google translate. Upwind/downwind being W/L and circular course beeing distance racing.  Hover your mouse over the small question mark, to get an explanation of the values. Don't mind the "no valid certificate", that's because all racing has been suspended by the Danish Sailing Association, beaucse of COVID so there are no valid certificates for any boats at the moment.

 

H-boat: https://translate.google.com/translate?sl=da&tl=en&u=https%3A%2F%2Fwebsejler.dk%2Fda%2Fbaad%2F32263

Quote
H-boat
    GPH   TCC
  672,0 0,995    
    TACIL   TACIM   TACIH
  852,8 662,4 586,6
    TAUDL   TAUDM   TAUDH
  1.122,4 825,8 713,2
    SV   dp   Wmin
  60,15 * *
    L   B   G   BogG
  7,10 1,80 3,22 0,151
    SSA   FA1   SAS   SAA
  15,33 10,08 32,12 0,00

 

Int. 806: https://translate.google.com/translate?sl=da&tl=en&u=https%3A%2F%2Fwebsejler.dk%2Fda%2Fbaad%2F11347

Quote
Int. 806
    GPH   TCC
  645,6 1,032    
    TACIL   TACIM   TACIH
  804,2 638,4 567,6
    TAUDL   TAUDM   TAUDH
  1.049,2 791,8 685,2
    SV   dp   Wmin
  58,86 * *
    L   B   G   BogG
  7,40 1,98 3,58 0,167
    SSA   FA1   SAS   SAA
  15,86 21,51 41,63 0,00

 

And by the way, of course I love "going saaailing" in high heels, they're really practical to wear when pulling up the heavy, gasoline powered propelled manhood extension out back on the tran(svestite)som, as you're probably familiar with :P

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  • 1 year later...

I'd google "portable fish finder" and see where that takes you. Some are available than run on AA batteries for small boats. Just leave the transducer bonded to the hull and grab the display and put in the cockpit and plug in the transducer when you want to anchor.

Otherwise something on a swing arm is probably fine too.

https://www.boatsafe.com/portable-fish-finder/

Because your boat doesn't have much freeboard you could also lean over the side with the flashlight style ones too.

https://www.itm.com/product/laylin-sm-5-water-depth-sounder?gclid=CjwKCAiA5t-OBhByEiwAhR-hm1Qcfp8lZVE-gPI6MNlTRNopey3YgxudLtU_x388BRC_QGKTgGoYdRoCoHAQAvD_BwE

 

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1 hour ago, Bull City said:

My need is mostly related to anchoring.

I don't know about models, less said about finders the better, but have one mounted since the previous owner and wonder if you're still thinking about placement?

Can report that it works nicely below the V-berth and useful that you can run the wires through the bilge without having to drill any new holes. It's just solid laminate as far as I know.
(Though it is an old unit that I may need to replace someday since it usually is accurate, but sometimes jumps from above 10m depth reading to 2m and that is just disquieting)

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5 hours ago, Bull City said:

I'm back in the market on this. My need is mostly related to anchoring.

I should add that there are charts of our lake, which is a 1950 Corps of Engineers creation, which show water depth, when the lake is at a certain level. Unfortunately, the lake level varies quite a bit, so the instant sounding would be very helpful. 

For anchoring, it's good to know how deep the water is, and given the sloping nature of the perimeter, it would be nice to see that. Will it keep me from running aground ever again? No.

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Hey Bull,

My Cal is on a Corp lake too.  Flooded in 88.  Lots of trees and structure under the water.  Great for fish...not great for anchors.  My old fish finder shows that crap nicely so I don't drop the hook in a sea of trees/branches and whatever.  Anchors don't come back from that.

 

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I wouldn't be without a sounder, it would be my first pick if I was told I could only have one instrument.

In Aus (which I know, you're not), the cheapest sounders are "fish finders", which attempt to show a few other details beside depth.  Sometimes not very successfully.

If you can live with the smallish digits, they do the job.

To find a suitable part of your hull, where you plan to glue your transducer, you should first place the transducer in a plastic bag, with enough water in the bag to cover the transducer.  Hold the bag and transducer against the hull and move it around until you get a reading.  Best done in deeper water.

I've glued transducers down with epoxy bog, polyester bog and silicon.  Just wriggle the transducer in the bog to eliminate bubbles.

Cheers

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The fish finder route seems good, since it would show the bottom contour, and presence of stumps and other objects that would like to snag my anchot. TheGarmin Garmin Striker 4 Fish Finder looks like a good option for $140. It requires connection to a 12v system, which is no problem.

I'd want get some idea of whether the transducer would work through my hull. When I bought the boat, it had a through hull transducer in the stem, which I removed and had the yard glass over the hole. That would probably be the place to mount this one

https://www.garmin.com/en-US/p/528812

image.png.caea5de03c8156afaee957eb7909044d.png

 

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Who sells those mounting arms that can swing something like a depth finder or chart plotter so it can be seen from the cockpit?

Edit: Found some. 

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The Garmin you linked to sucks down a full amp according to the Owners Manual. That would make it a no-go for me. 

This one is 0.2 amps: https://hawkeyeelectronics.com/collections/boat-mount/products/depthtrax-2b-boatmount-depth-finder

Or maybe just a lead line: https://www.yachtingmonthly.com/sailing-skills/practical-seamanship-leadlines-28316  Instructions for making one up here: http://navyandmarine.org/planspatterns/soundingline.htm 

Gotta love boating. Aargh!

 

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8 hours ago, Ron Swanson said:

The Garmin you linked to sucks down a full amp according to the Owners Manual. That would make it a no-go for me. 

This one is 0.2 amps: https://hawkeyeelectronics.com/collections/boat-mount/products/depthtrax-2b-boatmount-depth-finder

Or maybe just a lead line: https://www.yachtingmonthly.com/sailing-skills/practical-seamanship-leadlines-28316  Instructions for making one up here: http://navyandmarine.org/planspatterns/soundingline.htm 

Gotta love boating. Aargh!

Thanks for pointing that out. I wondered about the electrical draw, but wasn't able to figure it out. 

I don't anticipate running a depth/fish finder all the time - just when anchoring - so I don't think the draw would be a problem.

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1 hour ago, gkny said:

I thought that most of the "in-hull" transducers could not be used if the hull had a balsa core. 

I think that's true, however, there are some hull areas that are solid glass.

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