Making a new GPS compatible with an old boat

[Ex-Calif]

Originally Posted by nickfox45

So to clarify on the depth finder: that's the unit that'll need the transducer, correct? And I can either transom-mount that (as Ex-Calif suggested) or run it where the old one was? The boat is currently on the hard, so I have options as far as install goes.

The question is whether the currently installed transducer is working and compatible with your boat - and is a depth transducer and not connected to a speed transducer...

My bet is that it is a depth transducer and it may be working. That could save you a few bucks.

If it is not working you can install a unit that sees through the hull (as mentioned by others) or a transom mount.

As I was browsing I saw combo units that had speed, depth and water temp. I think the extra gizmos are cool.

As mentioned in the Chesapeake there is shallow water in a lot of places - I view a gps map and a depth gauge as 2 important items.

When you get to serious sailing boat speed is nice to have as well so you can verify the performance of your boat.

To be perfectly honest I have been sailing coastal waters for almost 9 years and almost never turn on the gps. I can see its necessity in fog or something but really 2 MKII eyeballs are all the nav I have needed.

[nickfox45]

Originally Posted by bmz

A Garmin 441 can be had for under $400 new, less used. I would sail without a depth sounder, but never without a chart plotter like the 441. A depth sounder tells you when you have run aground; a chart plotter not only shows you the depth under your boat but more importantly in front of it as well. Inasmuch as you are from Maryland, I presume you sail the Chesapeake. One of the great joys of sailing the Chesapeake is the literally hundreds of navigable rivers, creeks and inlets. However, the 6 foot contours on virtually all of them wiggle like a snake. If you don't have a chart plotter you are pretty well limited to navigating from marker to marker. If they truly have real chart plotter apps for cell phones you could skip all the other electronics and just sail with that.

Any place I should be looking for this at that price besides eBay?

And yes, I will be sailing in the Chesapeake, in the Solomons area.

[nickfox45]

Originally Posted by Ex-Calif

The question is whether the currently installed transducer is working and compatible with your boat - and is a depth transducer and not connected to a speed transducer...

My bet is that it is a depth transducer and it may be working. That could save you a few bucks.

If it is not working you can install a unit that sees through the hull (as mentioned by others) or a transom mount.

How can I tell whether the currently installed transducer is 1) working/compatible and 2) of the depth vs. speed variety?

[Ex-Calif]

Originally Posted by nickfox45

How can I tell whether the currently installed transducer is 1) working/compatible and 2) of the depth vs. speed variety?

Trace the wire to the hull - look on the outside - if there is a paddle wheel it is a speed log transducer. If flat and smooth it is a depth transducer. If nothing on the outside it is a thu hull depth transducer.

Checking operability would require a testing instrument - best to just plug it in to a gauge.

For the GPS have you seen this? Member has a handheld for sale. $100 is cheap in the boating world.

http://www.cruisersforum.com/forums/...or-141852.html

[Chuck Hawley]

I hate to swim against the current, but I have a different opinion.

First, while I love the Navionics app on my phone and mini iPad, they are too hard to see on a boat when exposed to sunlight. If you had a bimini, then maybe I would use them as my main GPS, but not on an open boat.

Second, any of the four or five inch Garmins would be a great choice. My preference would be to opt for a discounted 5" model (541s, 545s) since Garmin is constantly coming out with new models. I find the four inch models too small for my older eyes. A 4" model at retail would be $300.

Third, I would recommend you get the mode with the built-in sounder. First, it's really interesting to see the contours of the ocean floor, and the split screen display allows you to see the chart and fishfinder simultaneously. You absolutely want to have an in-hull transducer, which is easily added when you haul out next time. It is very unlikely that the old transducer is compatible. Use a "mushroom" nylon transducer and put it close to centerline.

Fourth, if you really like sailing and you want to upgrade to a Cat 27 in the future, you can frequently "borrow" the GPS from your current boat and move it to the new boat (except for the transducer).

Don't go cheap; spend some money and enjoy your boat.

Chuck

[bmz]

Originally Posted by nickfox45

Any place I should be looking for this at that price besides eBay?

And yes, I will be sailing in the Chesapeake, in the Solomons area.

Try googling "Garmin 441." That's what I did, and came up with two venders under $400. Also, I paid $350 for mine new about two years ago--I think it was Amazon. Correction: I bought a Garmin 421 new for $349 and a current Garmin Chesapeake chip on ebay for ~ $20. You should be able to match that total $ today.

[rwidman]

Most (perhaps all) of the current Garmin plotters are available with the world charts built in, no need for chart chips of each area. Much more convenient and less expensive in the long run.

[nickfox45]

If I buy a used Garmin 441 (or equivalent) on eBay (or elsewhere), should I expect to get any wiring or other connections to make this thing work? Looking at a model now but it appears to be only the unit with nothing else included.

[barnakiel]

I would keep it simple and avoid plotters unless where your are sailing is literally strewn with rocks and shallows. I have found a plain handheld GPS all we ever needed in 99.9% of our adventures (which included fjords, skerries, atolls and tidal rivers).

Keep it simple, understand the limitations, never rely on one method of finding your fix.

b.

[rwidman]

Originally Posted by nickfox45

If I buy a used Garmin 441 (or equivalent) on eBay (or elsewhere), should I expect to get any wiring or other connections to make this thing work? Looking at a model now but it appears to be only the unit with nothing else included.

If you buy a new one you will get what you need to hook it up. If you buy a used one that doesn't include the wiring it may be one that somebody snatched off a boat when the owner wasn't around.

Since you don't seem to know a lot about this, you would do better to get one in the box with all the cables, brackets and instructions on how to hook it up and use it.

[bmz]

Originally Posted by barnakiel

I would keep it simple and avoid plotters unless where your are sailing is literally strewn with rocks and shallows. I have found a plain handheld GPS all we ever needed in 99.9% of our adventures (which included fjords, skerries, atolls and tidal rivers).

Keep it simple, understand the limitations, never rely on one method of finding your fix.

b.

"One of the great joys of sailing the Chesapeake is the literally hundreds of navigable rivers, creeks and inlets. However, the 6 foot contours on virtually all of them wiggle like a snake. If you don't have a chart plotter you are pretty well limited to navigating from marker to marker."

[barnakiel]

Originally Posted by bmz

"One of the great joys of sailing the Chesapeake is the literally hundreds of navigable rivers, creeks and inlets. However, the 6 foot contours on virtually all of them wiggle like a snake. If you don't have a chart plotter you are pretty well limited to navigating from marker to marker."

I see.

For such waters I would get a center-boarder.

GPS or not, sooner or later one ends up on a shallow and, if the inlet is tidal, high and dry soon afterwards.

6ft seem heaps of water though, at least with any small craft.

b.