Conference unifix::sailing

re .0:

>>> Question: Can I avoid running aground having a fishfinder ?

A fishfinder is basically nothing more than a depthsounder. It will not 
make running aground more or less likely compared to using a standard 
sailing depthsounder.

We have an inexpensive (< $200 US) Apelco XCD250 fishfinder. It is
a rather neat device. It has a digital depth display, independent deep
and shallow water alarms (nice if you're trying to stay in a channel or
between depth contours), and a variable speed scrolling analog depth
display. The analog depth display allows you to see trends (eg, the
depth is increasing or decreasing and how rapidly) and to estimate the
roughness and hardness of the bottom. Should you care, it will also show on
the analog display any schools of fish that happen to be under you. The 
digital depth reading is supposed to be the bottom depth. 

The liquid crystal display is hard to read in bright sunlight, especially 
with polarized sunglasses. We use ours mostly for anchoring as the
display on our older Signet digital depthsounder is much easier to read.
Also, the physical design of the fishfinder is such that it cannot be 
bulkhead mounted. When using ours we temporarily mount it on the top 
step of the companionway ladder (where sooner or later someone will trip 
over it, no doubt). 

The transducer has the usual (200kHz) frequency and beam width. Ours is 
installed inside the hull in box filled with mineral oil. Nonetheless, 
it will read depths over 200 feet. 

By the way, with one depth sounder you know exactly what the depth is. 
With two, you're never quite certain since they'll rarely give the same 
reading. Our Apelco and Signet have disagreed by as much as 10%.  

Alan

    
    	I was a sonar designer in a past life- first for the Navy, then
    	for bottom charting by Scripps, Woods Hole, etc. So, I thought
    	I could just grab a high frequency transducer (for a narrow beam)
    	and mount it to look forward. 
    
    	No such luck.
    
    	1) Mounting is a PAIN. It has to be at least a half-foot deep to
    		avoid bubbles and get a good contact with water, so the 
    		keel is about it. Drill a keel, install wires? Not easy.
    
    	2) Flow noise. For comparison, open your sunroof. Nice easy
    		breezes, pretty quiet, even at 55, right? Now, go
    		into forward-looking mode. Stick your head OUT the 
    		sunroof. Not easy to hear the radio, right? Of course
    		with DSP, and other easy smarts, this may be gotten by
    		easily- especially with a rather blunt leading edge.
    
    	3) At 1-3 feet of depth, there's considerably more bubbles,
    		garbage, fish, etc. for the beam to hit, than a downward
    		facing beam. Again, smarts could help, but a penncil-thin
    		beam doesn't know a rock from a bubble from a bass. The 
    		fishfinder wins this one.
    
    	So the sonar companies will sell you what they've got, till 
    	somebody makes, say, a multielement transducer, adds the smarts
    	from the fishfinder AND false imaging. Not really all that tough
    	for a big company.
    
    	Scott.

    I too have an Apelco, a 350 model.
    
    "can I avoid running aground with a fishfinder"?
    
    Yes, but it depends.  My fishfinder (strictly downward looking)
    with transom transducer SAVED me from running into a BIG unmarked
    rock right in the middle of a lake.  The rock was about 6 inches under,
    just enough so I couldn't see it but certainly would have hit the damm
    thing.
    
    I usually run with my fishfinder on all the time... not looking for 
    fish, but watching the depth.  In the above incident the bottom started
    coming up, FAST, I chopped the throttle, and there was the rock smack
    in front of me. I stopped in time thanks to the fishfinder.
    
    If there was a rock on a horizontal bottom rather than a rock on a rise
    the fishfinder would never have seen the rock... I would have hit it
    before the transducer got near it.
    
    So, it depends on bottom characteristics.
    
    In general its a great AID to navigation, no question of that!  But
    it doesn't replace common sense and vigilence with YOUR EYES, ears
    and brain.
    
    I don't know how I got along without it now.
    
    Jeff

    One more thing.  A depthsounder give you typically a digital depth read
    out only.
    
    The fishfinder gives you a digital depth, AND a real time bottom
    display which shows BOTTOM TRENDS (rising?) which is a major advantage
    IMO over a depth sounder.
    
    Jeff

    They shound like great devices.
    
    Oh by the way, do they find fish ?

    Do they find fish?
    
    Oh.... yeah.... they do.... sort of.  At least I have never been SURE that the
    little fish that cross the screen are really fish, but I think alot
    of them are.  Any object that has the right density the fishfinder
    will think is a fish and display it as a fish.
    
    Actually they DO find fish, the problem is telling what ARE NOT fish.
    And, IMO they should't be called fish finders.  That is a marketing
    gimick to lure fishermen into buying them.  They should be called
    for what they are.... SONAR, which, by the way, can also spot fish.
    
    Jeff

    thanks for the info.
    
    I'm going to buy  a fishfinder. Only one question left.
    What does it display ? 
    
    
    
                           /-------\
    		   /------/	    \ 
     1      -------/                  \------------------     2
    
    
    
    is 1 left and 2 right of your sounder or
    
    is 1 forward and 2 behind of you sounder or
    
    what ?
    
    
    thanks    Peter
      

    Peter... it displays one point in real time... the right hand
    extreme point of the display.  Moving to the left as on graph paper
    type movement is the history of the bottom passing under you.  You
    can vary the speed of the 'graph paper' movement, vary the scale,
    put in bottom or shallow water alarms, fish alarm, and often temp
    in F or C, speed of the boat in knots, mph, or kph.  They can be
    a veritable instrument panel in one, which mine is.  Oh, you can
    also zoom in on bottom features.
    
    A bottom  of the line fishfinder won't give you boat speed or water
    temp, but will give you most of the other features.
    
    The hardness of the bottom is also represented by the depth of the
    band of the display... i.e.  a soft bottom might look like this:
    
    XXXXXXXXXXXXXXXXXXXX
    
    and a hard bottom
    
    xxxxxxxxxxxxxxxxxxx
    
    but it takes practice.... quite a bit of it in fact to extract all the
    info the readout is telling you.
    
    Jeff

    
    	This months Practical Sailor describes a forward-looker, from
    	Britain. About $US800. Letter was pretty sparse on info, but
    	gave address & phone #. Would be mighty nice, in Boston Harbor
    	area...
    
    	BiffBangCrashOuch!

    OK, everything clear. Thanks for the clarification and the help.
    
    Peter
    
    

    I can get the cheapest "Eagle" either in Germany or Switzerland.
    Nothing else.
    
    U.K is offering all models thru mailorder. But no pricing and no
    details.
    
    I have a 1991 spring "Bliss marine" catalog. The price range at that
    time was from 133$ for the cheapest Hummingbird to 500$ for the 3D
    from Hummingbird.
    3 models from "Eagle". The cheaper for 140$ and then going up to 280$
    for the model with seatemperatur and speed.
    
    I have no access to more info.
    
    I'm looking for a "fishfinder" in LCD technology, no speed/temperatur
    sensor, transom mounted (but I'm going to use it inboard with the oil
    and do not worry about the reduced sensitivity). 
    
    Question: is there anything new on the US market ? If possible from
    Bliss marine, as I have all the information I need to order from them
    which covers the above requirements ?
    
    If there is nothing new, I'm going to order the Eagle in the medium
    price range (1991 $170) and hope for the best.
    
    Peter 

re .11:

Peter,

We are quite happy with our Apelco XCD-250. It is more user-friendly
than some others I've looked at and it does work well. The XCD-250 is a 
depth-only unit, no water temperature or boat speed or loran interface 
or anything else. Price is about $180 US, as I recall.

Bliss Marine is not the best choice of vendor. I much prefer West
Marine. I'll check their current catalog tonight. 

Alan

    Peter, I second the recommendation for an APELCO XD 250.
    
    The only complaint I have against LCD fishfinders is that the display
    is very hard to read when wearing polarized sunglasses.
    
    Jeff

Peter,

Here's some current UK prices all in UK pounds sterling from PBO March93

                         �		Supplier          tel
HUMMINGBIRD LCR400 1D	119.90         	TELESONIC **    (0)71 837 4106
     "        3D        299		LYC             (0)71 247 0521
EAGLE SUPRA 1D		159		PUMPKIN MARINE  (0)71 480 6630
(Apelco not listed at all)


** listed as special offer so price won't last long.

These prices include VAT, so can get 17.5% removed, then add post and import
tax.  All take plastic by phone. UK code is +44  and leave out the "0" on the 
area code.let me know by mail if you have any problems.   
Steve

    Oh thanks for the help.
    
    I checked this in my old Bliss Marine Catalog and I can not
    use the Apelco. My current depthfinder is hanging from the wheelhouse
    roof and thats the only space left. The Apelco can only be mounted
    on a horizontal surface. The Eagle can be converted somehow to
    be "hanged".
    
    So it must be an Eagle.  Alan, can you provide me with the FAX #
    of your prefered mailorder house ? Even if it is not much cheaper,
    but I need a new source for equipment anyway. Alan, do you have
    the price for an Eagle Magna and the price for an Eagle Fish ID II ?
    
    The Eagle Ultra is to expensiv and has to many features.
    
    Peter 

    West Marine just opened a store in E. Greenwich, RI. Their number
    is (401) 884-0900. They are close to Rt 95, on Division St.

re .15:

Peter,

West Marine's FAX number for international orders is 408-728-4360. 
Telephone order number is 408-728-4430. They accept MasterCard, Visa,
American Express, and Discover plastic money. West's customer service is 
outstanding, in my experience.

Bad news is that they don't stock (according to their 1993 master 
catalog) the bottom of the line Eagle. The cheapest Eagle in the catalog 
is the Magna II Plus, which includes water temperature and boat speed 
for $259 US. (West also doesn't list the Apelco fishfinders, but BOAT/US 
does.)

The contributors to the powerboats notesfile (VICKI::BOATS) and the 
fishing notesfile  (I don't know where this one is) probably know much
more about fishfinders and where to buy them. 

Alan

    Overton's
    Eagle Supra I.D. $ 134.95
    Eagle Magna II 169.95 (with temp/distance log display 219.95)
    
    tel.from outside US 919-355-7600
    credit card orders may be placed any time via Fax 919-355-2923.
    
    Overton's is a powerbot,fishing catalog and I am impress with
    some of their prices.
    Could it be that powerboters became poor like us :^)
    

    I've had some success getting non catalog merchandise from West Marine.
    
    After listening to me explain what I needed, the telephone order taker
    looked up the item in the manufacturer's catalog and had them ship
    directly to me.  Since it was an East coast outfit, the item arrived
    much sooner than it would have if it were a regularly stocked item.
    
    They, and probably any other marine electronics vendor, could get the
    low end fish finder for you if you tell them what you want.
    
     

    Thank you very much for the info. I will order one soon.
    
    Alan, I checked the fishing notesfile. Looks like, a lot of people
    own an Eagle, with some Apelco's. Hummingbirds are not very
    popular, but nobody knows why.
    
    Peter 

    Hi Peter,
    		Should you come down to Geneva, I could show you the
    Eagle ID fitted to my sailing boat. Works great & it is the second one
    I've owned. I mount the transducer off the ladder whilst sailing.
    and the display is mounted on a 30cm square board in the cockpit, all
    easily removeable when I lock up the boat.
    
    		I enjoy fishing in light winds & can see tons of fish.
    However the problem is that the hungry fish are not highlighted.
    It is fun to see the bottom up to 300meters (1000ft) & the for ever
    changing display keeps kids fully occupied, just like TV.
    								Nick

    Hi Nick, you still alive ?  We met some 17 years ago in Paris, you as
    teacher and me as a newhire doing my first PDP11 courses. No travel
    this days anymore. Thanks for the offer.
    
    
    I will order next week an Eagle, either in the UK or in the US. I have
    not decided yet. 
    
    
    Peter

    Alan, I understand now, why you are biased towards West Marine.
    
    I send out a FAX to Bliss, West and Cruisermart (UK). West replayed
    the same working day, Cruisermart after 2 days and Bliss not yet.
    
    I have ordered now from West.
    
    Peter 

    I received my Magna II from West last week and installed it in the
    boat. I glued the transducer to the hull and I was all set.
    
    It works fine, goes down to 900 feet. My mooring used to be at 135
    feet with my old dephtmeter, now its at 113 feet. I will soon
    check the real depht manualy.
    
    Thanks everybody for the help.
    
    Peter
     

    Peter,
    
    Where did you glue the transducer and how much hull/keel are you
    sending the signal through? I'm wanting to do this in my boat as well
    and am trying to figure out how to use a transom mounted transducer
    without having to spend an extra $80 for the thru-hull version, thus
    keeping the existing one in place as well.
    
    What did you use to glue it in place with?
    
    Thanks,
    Robert

    re:  .25
    
    My boat has a transducer that fires through the hull. The transducer
    is mounted in a vertical tube which is glued to the glass-fibre hull with
    Araldite. The glue also acts as a seal between tube and hull for about 
    1/2 inch of castor oil in the bottom of the tube, enough to cover the 
    lower face of the transducer. The oil "connects" the transducer output 
    to the hull which in turn connects with the water. This arrangement 
    allows for the transducer to fire vertically down even though the bilge 
    has already started to turn up by about 15 degrees. The transducer is 
    about 2 foot behind the trailing edge of the keel and 1 foot off the 
    hull fore/aft centre-line. I'm guessing that puts it outside of the 
    main keel turbulance. I've no idea what the hull thickness is at that
    point since I have a basic aversion to holes in boats. 
    
    The transducer is intended for firing through the hull and is sealed 
    against the oil. The make is Seafarer (UK), a cheap unit good for 
    about 130 foot. I believe its possible to damage a transducer by 
    firing it without a load(=seawater or oil+seawater) so take care.
     
    Steve
    

    My transducer is mounted in a 6" pvc "cleanout" from the plumbing
    supply house. I countoured the bottom to match the curve of the hull,
    stuck it down with epoxy and filled it w/ mineral oil. It has been
    working fine for 4 years. I get readings up to 199', where my
    depthsounder runs out of digits.
     
    "No-holes-below-the-waterline-Bill"
    

	I'm intending to install a depth guage this spring. I was very
	intrigued by the previous two replies as avoiding another 
	through-hole appeals to me.

	Does anyone else out there use the "internal method" with some
	some container filled with mineral oil?

	DID ANYONE EXPERIENCE POOR RESULTS?

	Mike

I've used the internal method with three different depthsounders -- it 
worked well with all three. I'm currently using an epoxy-coated mineral 
oil-filled plywood box to hold the transducer for my backup 
depthsounder.

One caution: This only works with a solid fiberglass hull. If the hull 
is foam or balsa cored, you'll need to cut a hole through the hull.

    
    
    	Or, what I did for a friend who had a Baltek-cored hull: I knew
    that the internal layer of glass was pretty thin, compared to the
    overall thickness. So I carefully cut a `glass plug from the inside,
    chiseled out the balsa, and glued in the thru-hull, making it as
    strong, I hope, as the surrounding structure. Certainly stiffer than
    the core!
    
    	Now, service is pretty much impossible, but the sounder has been OK
    for 6 years now. Better than my boatyard-installed unit. I don't think
    that gain needed adjustment because of the install.
    
    	FWIW-
    
    	Scott_who_had_to_fair_the_transducer_in.
    

    I did an internal thru the glass shot as well.. many years .. no
    problems.
    Bob

    My previous echosunder was factory installed. It used a tube, glued
    in and filled with oil. It was leeking from the beginning, and after
    1 year I gave up, refilling the tube. I used epoxi and it worked fine
    until 2 month ago.
    The new tranceiver from Eagle looks completly different. Its eggshaped
    and not designed to be put in oil. The manual from Eagle recommanded
    to glue it directly to the hull. (if the hull is solid) . I was
    very sceptical:
    
    
                          /
    		keel	 / hull
                        / 
    		----   /
    	           |  /
    		   |O/ transducer
                   |/
    		   |
    		   |
    		   |
    
    I could not find a place in the bilge, where i could glue in the
    tranducer on a flat surface. So I moved the boat to 100 feet of water,
    put a lot of Araldit between the keel and the body of the hull, and it
    worked! As it takes 5 minutes to harden, I had plenty of time to
    check that the fishfinder was working properly.
    

    Re: .28
    
    On a previous sailboat I internally mounted the transducer on the
    center-line, aft of the fin keel.  The approach was to first build up a
    flat and level surface on the hull by constructing a paper 'dam' about
    2" in diameter, then filling it with quick hardening epoxy.  After the
    epoxy had cured I lightly sanded the surface (using a block) to insure
    that it was flat.  The final step was to mount the transducer (which
    also had a flat surface) to the epoxy by using a very thin layer of
    silicone sealant.
    
    This approach worked great on a rather thin hulled Catalina 27.  The
    Coastal Navigator depth sounder would easily read to 200'. This
    approach avoided another hole in the hull, and having to deal with
    mineral oil plus container et al.
    
    	Howard

    Thanks for all the input!
    
    Next question: I talked to the folks in the newly opended West Marine
    here in Dallas. They recommend I use a transducer that outputs 100watts
    of signal, vs the more standard 35watts of signal since I'm going to be
    shooting through about a 1.25" fiberglass hull (a racing machine, it's
    not). Interphase makes the units that have this kind of output,
    Hummingbird has the 35w output. Anyone ever hearing of this making a
    difference as far as depth penetration and accuracy are concerned? I
    have a solid glass hull. No coring.

re .last:

Before you get a depthsounder with a higher output power, you might want 
to check the 12V DC input power. Depending on your battery capacity, 
recharging system, and how much you use the depthsounder, this might be
an important consideration. 

Alan

    re: -1
    
    
    100 watt is not the DC load. My Eagle is sending with 35 watts and
    hardly uses more then 350 mA/12 V. 
    
    I would not bother to buy a new transducer. I get down to 900+ feets
    with the standard 35 watt transducer and it has to go thru at least
    15 mm of Araldit before it hits the hull.
    
    Peter

(I think) I remember the literature with my Seafarer depth sounder saying 
that the transducer output power is 80 Watts, but the duty cycle is v.short, 
something like 1/4 millisecond every second. 

This makes the drain on the battery very low. The Seafarer runs for 100 hours 
on 6 penlight cells (0.5 amp-hours).  I guess there is no reason for other 
depth sounders to be very "juicy". Fit and forget.
Steve

re .37:

Ah, but not all depthsounders are the same. I have two. One draws
between 0.4 and 0.9 amps DC depending on the brightness of the display. 
The other draws <0.5 amp DC. Both are fairly low power, shallow water 
(<300') depthsounders.