Help newbie out with basic GPS/Depth options for a cruiser

rtp

Member
May 9, 2020
37
Boat Info
98 Sundancer 270 wide-beam
Engines
Mercruiser 7.4L MPI
Hey guys,

I've had 'special' GPSes before for my motorcycles before pretty much going to RAM mounted phone, but am a bit lost when it comes to marine options for our new (to us - 1998) 270 SDA.. it has a depth finder currently with a PO replaced (1998-era) transducer, single gauge in the dash with depth which does work, but I'd prefer to at least have some depth maps in combination with GPS... I'd be OK if there were a GPS option that used decent charts including depth as the base, and glancing at the existing depthfinder for confirmation or to use as an offset vs that data.

The lake we're slipped in has a fair amount of depth variance and some sections that get fairly shallow. We don't fish currently, so the main use is really simply navigation and depth. I'm fine with adding a RAM mount or other mount to the dash, also fine if there's an option of accurate charts not involving a new through-hull transducer, although I have questions on how accurate they are.

Not a huge fan of 'special' GPS units due to the never-ending behavior of paying for 'good' maps, or 'updated maps,' and am aware some units seem to come with more useful to not-at-all-useful base maps... could really use some help sorting out options here.

I think there are basically two options here:
1. phone (IOS/iPhone) or iPad based - would provide nav but I'm assuming limited to whatever random depth charts can be used.. ?

2. Some kind of GPS/chartplotter with way too many options to sort - would prefer not adding a new through-hull at the moment as she's likely in the slip until coming out off-season and I'd need to borrow a truck to pull her out (sorting this for future..). I think I've read that some transducers can be used inside the hull although have no idea to accuracy or how/where they'd mount, have seen the 'transom tails' which don't seem a great idea for an SDA to me...
If I wind up with another specialty GPS unit with through-hull required, do they start with basic depth maps and I could use until I install the through-hull transducer in the future?

I see options in the $400 - > $3000 range at this point, strongly prefer < $1K on this one or a phone or tablet option if a viable one exists.
 
Yeah, it will likely be a Garmin unit.

What I'm uncertain of is:
  • Transducers - many of them come with transom-mount transducers. My depth-finder has a through-hull - is anyone using a transom mount on a cruiser/does this make sense or just assume adding a through hull?
  • Usefulness of side-view, down-view etc. variations - it would be nice to be able to update depth and contour maps via the transducer, but I'm completely unsure of the limitations here:
    • What are the speed limitations if any? Are the 'bottom images'/clear-Vu only really when at trolling speeds?
    • Does anything beyond down-vue make sense for a non-fishing boat hitting up to 40MPH or so?
  • Differences in map sets. This is where I tend to get pissed off with Garmin and others. g2 Lakes, G3, Lake HD vs Ultra vs ... ... ??
  • For my purpose, is it worth getting a generation back used higher end or just get something like one of the current general EchoMap variants?
No plans to add a $~2K panoptic transducer into the mix, nor radar dome any time soon.
 
Navionics has gps maps that include depth. They update daily based upon people using their depth finders and that data making it back to Navionics (Sonar Chart, and Sonar Chart Live). Garmin bought Navionics, not sure if they have integrated their maps yet. I use Navionics on my Simrad showing the Sonar Chart (as opposed to the included charts or the government charts). I’ve only been on Dale Hollow Lake in TN with my maps on my phone, but it worked great there, and works great here in coastal FL.
 
I suppose that is my biggest question....on how to update actual depths and contours from the base maps.
Will my maps update if I use one of the numerous transducers available from Garmin (e.g. GT54UHD, etc.)?
If I use the base unit only, can I get depth and contour updates from others if I do NOT connect a transducer of my own?

The lake she's slipped in isn't big enough to where we'd get 'lost' at least not more than it takes to pull up google maps on a phone for a minute, but having accurate depth readings and ability to plot even a basic course to avoid the shallow areas is what's important to me in this case.
 
Wound up getting a 93sv UHD with transom-mount transducer. TBD on if I install the transducer or not, but it will be end of season if I do.

I'm amazed what Garmin and others charge for <$250 in retail price parts (display, power supply, raspberry PI or equivalent), but more importantly - no matter what I do, I seem to be unable to display actual hazard buoys on either the AC App OR on the GPS - this is sort of a problem, considering the data is there both on Navionics web and the Garmin AC online maps. Looks like Navionics data is 'mostly' integrated in LakeVu G3, although I seem to also not be seeing contributed hazard callouts (big rock a few feet under the surface is there in Navionics, nada on AC or on GPS, even with ActiveCommunity local content enabled.

Any clue why I have no hazard buoys at all?
Navionics online:
upload_2020-8-8_13-9-19.png


AC Online:
upload_2020-8-8_13-9-43.png


AC App on iPad - missing buoys
upload_2020-8-8_13-10-6.png


And on GPS:
upload_2020-8-8_13-10-25.png
 
Not familiar with Garmin, but most devices can turn on/off certain items. Also, on my Simrad, after inserting my navionics card, I had to go into the system and tell it to display the navionics for Map Source. It defailults to the base maps included (also helps if you insert the card all the way, only lost 5 minutes of my life trying to figure that one out!) Below is my navionics subscription showing the same area.

27688783-980C-43C1-9212-E44EFE2443D1.jpeg
 
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Wound up getting a 93sv UHD with transom-mount transducer. TBD on if I install the transducer or not, but it will be end of season if I do.

I'm amazed what Garmin and others charge for <$250 in retail price parts (display, power supply, raspberry PI or equivalent), but more importantly - no matter what I do, I seem to be unable to display actual hazard buoys on either the AC App OR on the GPS - this is sort of a problem, considering the data is there both on Navionics web and the Garmin AC online maps. Looks like Navionics data is 'mostly' integrated in LakeVu G3, although I seem to also not be seeing contributed hazard callouts (big rock a few feet under the surface is there in Navionics, nada on AC or on GPS, even with ActiveCommunity local content enabled.

Any clue why I have no hazard buoys at all?
Navionics online:
View attachment 89838

AC Online:
View attachment 89839

AC App on iPad - missing buoys
View attachment 89840

And on GPS:
View attachment 89841

On my Humminbird with Navionics you have to go into Settings, Select A Chart Detail Level, Navigation.
Bouys etc will then be displayed.
 
I have a Lowrance chart plotter that’s older than the hills. It still works good but I know it will have to be replaced sooner or later. It looks like an iPad with the navionics app may be a good option?
 
Not familiar with Garmin, but most devices can turn on/off certain items. Also, on my Simrad, after inserting my navionics card, I had to go into the system and tell it to display the navionics for Map Source. It defailults to the base maps included (also helps if you insert the card all the way, only lost 5 minutes of my life trying to figure that one out!) Below is my navionics subscription showing the same area.

View attachment 89857

Yep, your pic is pretty much a match for what both Navionics online maps and ActiveCaptain maps show online.

I've been all over the menu system in both the AC app and in the GPS itself trying to sort.
The only thing I seem to have is an option to select 'nav aids' of NOAA and IALA. Dug into the echomap manual - unfortunately there doesn't seem to be any LakeVu g3 specific manual...and some vague statements that contradict each other in some places, e.g. stating the fishing map doesn't display buoys, to reduce satellite overlay for higher detail elsewhere...which later seemed to contradict themselves elsewhere. Have been in and out of nav and fishing maps, no net difference - still no buoys.

I sent an email off to Garmin - I might be able to call them but of course, likely won't be calling them with the unit in front of me then...although I haven't finalized the install yet.

My SDA 270 doesn't have any chance of embedding it in the helm, so going RAM mount. If anyone has any clean-ish install pics or links, please send 'em my way. Right now, it seems the best placement will be the RAM ball base sitting almost in front of the gas gauge on the right hand side of the helm, and will use the RAM arm to position as needed. Of course, I need to sort powering it, and routing of cables. For the power cable bundle, I think I'm going to slightly widen one of the ram mount base holes, snip off the inline fuse, feed it through and then solder and heat-shrink the fuse back onto the line. Need to dig out the manual and see if I can decipher where to get ACC ON power - looks like I should be able to tap off the ignition switch itself. Surprised to see the 'cigarette lighter' socket claiming 15A, so could certainly get power from there although at least on mine, it seems to be wired to constant power. I am seeing a ground bar on the right starboard side of the hull, so there's the ground unless I wire directly to a switch.. I'm thinking will seal off the wire run through the bracket and helm with some marine sealant or silicon, but then go back and find a boot I can put over it as well.

Once it comes to later adding a transducer, I'm not seeing a clean way to avoid another hole in the helm, moreso as those cables have a fat connector on them. Let me know if anyone has any good thoughts on wiring/cable routing.

The current depth finder has a cable labeled Airmar P23 - which I'm trying to sort if I can plug into the echomap temporarily simply to get depth readings. If I can, then I can use the depth sounder existing switch on the help to power the GPS. I'll eventually do the UHD-54 transom mount or replace the through-hull transducer, but probably not until she comes out of the water towards end of season, so any thoughts appreciated here as well.
 
On my Humminbird with Navionics you have to go into Settings, Select A Chart Detail Level, Navigation.
Bouys etc will then be displayed.

See prior response - have looked everywhere, including setting charts to max detail + various other options. So far, a no go - no buoys yet.

On Garmin, you select the chart type first, e.g. Nav, Fishing, or combo and it seems to keep chart settings specific to each one alongside it, but have tried pretty much all options for both Nav and fishing maps.
 
According to the manual, they will display in navigation charts, but the buoys look odd. Not an icon I would have designed... Seems pretty easy to miss...
D912AC3B-C026-43D4-A2BA-584EB1C3A4B0.jpeg
 

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