Marine Electronics and Navigation

[knewsom]

Ok fellas, I know a few of you know more than I could ever hope to about GPS, electronics, navigation, etc... and I am coming to you with a bit of a conundrum.

I purchased a boat some months ago, and have been slowly getting it up to snuff (slowly because I've actually been working, and other projects keep interrupting progress, but there is progress nonetheless). The next weeks' daylight hours are devoted to completing this task.

The boat came with a transducer for sonar, fish/depth-finding already installed, but of course the head unit is missing. Although my primary intended use of this boat 23' fishing boat is in coastal waters, and I know most of these waters well enough (having grown up here, and fished, surfed, and sailed all over), I'm going to need navigational aid for safety and longer trips, and I definitely need a working fish finder.

I've been hitting ebay, and looking at head units without transducers, thinking maybe it makes sense to pair mine with a new one, but I'm concerned about compatibility, so that option seems poor. Also, it doesn't seem as though I'd even save much (if anything) over buying one new or complete.

Chartplotters seem extremely expensive. There are a few that are sub-$300, and they actually look decent, and a few even incorporate sonar. The trouble is, the screen size is about the same as my iPhone, and trying to combine those functions in such a miniscule display seems inherently problematic.

Proposed solution - purchase cheap depth/fishfinder for dedicated fishfinding needs. Use iPhone in lifeproof case with iNavx for dedicated navigation onboard. Benefits include GPS built-in battery backup, detailed charts, and some pretty sick functionality. Potential problems include navigational accuracy (though in all truth, my iPhone 4GS has access to the russian GPS as well, and has proven itself numerous times to be exceptionally useful and accurate as a GPS unit), as well as utilizing a touch-screen interface on a small device when my hands are covered in fish guts and cold.

I will of course keep paper charts and manual navigational instruments onboard, but I just can't justify shelling out thousands of dollars for a sophisticated system, especially when I could build a solid-state marine PC for a few hundred bucks that will run software and accomplish more than those units ever could. That just seems like overkill (and more effort/expense than my current proposed solution).

Suggestions?

 

[Mongo]

Do you want the Eaglelite 480 I had at the race? Cheap...pm or call me

 

[p m]

Sounds like a Motorola tablet + USB GPS antenna+receiver unit to me.

 

[Le shed]

Therer are so many transducers out there now it is hard to mix and match a head unit with a transducer. The old way was to go for high frequency for shalllow water, 120-200khz, and low frequency, 25-50KHZ, for deep water. These were usually coil tansducers or piezo electric type. You had to match the frequency of the head unit/transceiver with the transducer. Some transducers are through the hull or outside the hull and some can mount inside the hull.
The modern stuff now has smart transducers that use a propietory bus i.e Raymarine sealink or RS422 etc and the head unit is just a display with a program. You will have to identify what transducer you have to know what you can or cannot connect to it. There is also the matter of power matching too. Could be a 100W one or a 600W one. They have to match that way too. Easiest route is identify what transducer you have and go for its matching head unit.
As far as navigation system goes the PC route is o.k. You can download free NOAA raster or vector charts from their website. You may need to find a program to display them though. Common ones are "The Captain" or Furuno "MaxSea' but all cost real money. There are other ones out there so hunt around. Charts take up a lot of memory so allow for it. For sensors go with a USB connection type but again most marine antennas are proprietory connections i.e TNC, BNC, UHF.
I use a laptop and a De Lorme puck GPS antenna for sea trials and it works pretty well with the free charts but I have a copy of MaxSea that runs it all.
Good luck.
Bill B

 

[knewsom]

Thanks for the info guys...

Le shed, I've been scratching my head over the last few hours figuring out the details of different head units, transducers, etc. There are a LOT of head units for sale out there with no transducer, I'm guessing about half are stolen, the other half are the casualties of upgrades.

Like I said before, I really don't want to go the route of a homebuilt PC or even a dedicated tablet for this... it just seems like overkill for a fishing boat (even if I do end up taking it someplace a bit further like Catalina or Baja), and in any case, it's more money than I want to spend. I really need to keep things under a budget with this boat, otherwise it'll spiral out of control, and fast.

The transducer currently on the boat is a Garmin, and while I've found a number of good and fairly affordably garmin fishfinders, I'm not finding anything reasonably priced by them that's a combo unit.

Mongo, that Eagle won't work with my transducer, so I'd need to source another one... I think this might work with it though.

I'm kinda starting to lean towards this Hummingbird combo unit. The charts don't look great (30m per pixel), but the sonar looks decent, and it's well reviewed. Bigger screen than the iPhone too, though it's still only 4", and black and white.

 

[kennith]

I love my Garmin 478. I've not used it in a boat, but the the marine functions seem fairly comprehensive for a dual purpose unit. Being delivered with good charts is nice, as well.

Garmin also offers a comprehensive fish-finder addition for the 478, providing the unit more flexibility for everyday land and marine use. Being XM WX capable is quite good, and allows you access to a variety of weather features for live reference.

Overall it's a fine product, and I love it. It's old-school, for starters. It's got none of that sexy interfaced touch screen bullshit. It's very well sealed, properly durable, and simple to operate. Satellite locks are fast and reliable, and, accuracy is very good.

I've pitted my old IIIc up against a Trimble GeoXT with outstanding results. It's accuracy diameter was only 18 inches off once three locks were averaged. Sounds bad, but the Trimble took a shit-load more than three. So far as reception is concerned, the IIIc flatly embarrassed the Trimble. The only way to come close to the IIIc's performance was to wear that dumb-ass Trimble antenna-hat.

That matters because the 478 is better than the IIIc on all accounts. It's by no means a toy. It's a tool capable of professional use in harsh environments.

I'm not suggesting you buy one. I'm only suggesting you weigh it as an option. Look it up and browse it's capabilities. the thing is still relevant, and it's a damn sight better than that newfangled smart-phone/tablet bullshit, and it works a hell of a lot better than it's replacement.

There is only one issue, but I consider it a benefit. It's got actual buttons. That means it doesn't have a keyboard of any kind. That means it's back to scrolling through letters and numbers, if you buy one. It doesn't bother me. I'd rather have that than a touch screen.

It can be connected to a computer, though. I'm not sure what it does, as I haven't had a reason to use it while connected yet, but the feature is there. My Toughbook has a touch screen, so it's possible I could use it with the computer and the touch screen, but I can't be bothered to find out. I really don't care.

Anyway, you might want to consider one, is all. I wanted one so bad I paid nearly grand for the thing just over a year ago (might have been longer than that). That ought to tell you how much I like it. I cranked out a thousand bucks for something that had been superseded several years before.

I still think it was worth every single penny.

Cheers,

Kennith

Edit: If you search hard enough, you can find a flush mount that will french it into your console. It's made for the 478's aviation cousin, but it works.

 

[jonesy66]

Kris...go cheap on the GPS, they all work well enough for boating purposes. Then buy a good fish finder/depth sounder with water temp. Transom mount is usually the solution most come with but the thru hull type are the best and most accurate. You can also get a combo unit like Garmin sells but a REALLY good fish finder....COLOR is the bomb.

 

[knewsom]

Jonesy, thanks for the advice! What's more important, resolution or a color display? There is a Garmin 300C on fleabayfor $150... it looks attractive, but the resolution is the same as the hummingbird 365i I've been eyeing, and the display is actually half an inch larger on the 'bird.

Kennith, that GPS unit looks very nice, but at $800 or so, I'll pass - budget is important. Spend too much and Lady Luck will turn on me (IE the wife).

 

[kennith]

If that's the case, she'd probably murder me if she ever had to use it, because you'd flip as soon as she started a-fussin'.

Confused Wife: "How the fuck do I tell this thing where I want to go?"

Worried Knewsom: "See that D-Pad? It's like a Nintendo. You just go up and down to scroll through all the letters and numbers until you find the one you want."

Irritated Wife: "That's all?"

Seriously worried Knewsom: "Well, not really. After that, you push the button to the right, and start all over again for the next letter, and keep doing that until you enter all your information."

Irate Wife: "How much did we pay for this piece of junk?!"

Benedict Arnold: "Kennith told me to!"

You've got to really want what it offers to see the point in it. I should have mentioned that everyone else in your life will hate you for owning it.

On your most recent question: Color is always worth it, unless the resolution totally sucks.

Cheers,

Kennith

 

[msggunny]

I have a HDS 7 Lowrance for mine. I love it.

Having a boat is almost worse than owning a rover though.

 

[knewsom]

Agreed about owning a boat being worse than owning a Rover. I'm going to try and absorb some of the cost by taking people on trips when I'm not working.

I bought the Garmin 300C on fleabay. Going to sell whichever of the transducers I don't use to help absorb the cost, then I'm buying a Lifeproof iPhone case and that chart program. All told, it's going to cost about the same as the Hummingbird, but I've heard from a few people that the Hummingbirds are just not very good. Looking at the charts that came with it anyways, they were low-rez, and buying a higher quality one was at least a hundred bucks more. Also, screen-size was only 4". With this setup now, I'll have two 3.5" screens (one for sonar one for nav), and charts as detailed as paper charts. Sure, my iPhone may not be as good as Kennith's Garmin 478, and I might get frustrated with the touch screen once and awhile, but really, GPS is less important than the sonar. This is not a boat I'm going to take any epic voyages in... I'm mostly going to stay in sight of the shore, and even if I get lost and GPS fails, I know enough to find my way back based on compass bearing and landmarks. The only time I'd really have to rely on it is when it's foggy, and even then I think I could pilot the boat back in without it.

Maybe I'll buy a stylus and keep it on my boat.

 

[jonesy66]

Good one Kris. You will be happy. I doubt you will be going offshore, out of site of land so GPS will be used primarily for marking your honey holes! If the iPhone turns out to be a pain in the ass a really good alternative is the hand held Garmin Trex, beauty about that is you take it with you when you do a charter and MOB all the honey holes you go to with the guide...then go back at your leisure, just don't let him see you doing it
Additionally, you can use it for hiking and Roving!