I think it depends a lot on what you want to get out of the unit / ReefMaster. Do you want to put maps back on to the unit? What is your price range?

You state that you want to be able to run an external GPS (most units will take an external GPS input I believe), but what are you hoping to achieve by this? One issue with logging on units is that the file formats that they log to do not always allow for the precision you might hope for. E.g. Lowrance units log position to approximately 1m resolution. This isn't a problem for depth mapping, but it is an issue when creating sidescan mosaics - we need to smooth the track path before it can be used. Perhaps even more important than pin-point positional accuracy when creating sidescan mosaics is headings. Although RM doesn't use headings yet, our Sonar Viewer does, and work is well advanced on bringing this over to RM. We have found that we get very good results when logging GPS and headings independently of the unit - take a look at this forum post for an example. External GPS log/sonar log synchronisation is coming as a feature towards the end of this year.

A unit that I have been using recently that seems to fit your specifications is the new Elite Ti from Lowrance. This is small (I use the 7"), well priced and logs 2D, DS and SS, and does so to the same standard as the more expensive units. Lowrance are the only real choice if you want to show your maps on the unit. If that isn't important to you then the HB side imaging units produce excellent sidescan logs that can be used in RM.

What sort of depths will you be mapping? The deeper it gets, the more important your ducer gets. As for pure quality of 2D-sonar, Lowrance/Simrad/ Raymarine are equal at the higher pricepoints, but you can't use your maps back in a Raymarine plotter. (Which is by no means RMs fault, but still a shame.)

HI,
Thanks for your replies. I want to feed NMEA 0183 RTK (cm accurate) position into the head unit. I have this in hand, although I will need to sort the handshake out with the sonar unit.
From my research the Humminbird sidescan unit 9" model supports GPS external. (Oddly the 5" and 7" down only does) The 9" is too big for my purpose. I will not be using the head unit for maps. It will take in the external GPS, inputs from the transducers, process the data and store to SD.
I will then take SD to Reefmaster.
My problem is that i need best transducer for down/sidescan that connects to a decent headunit that hopefully can take in accurate decimeter positions and save to a SD card.

From feedback here, and that fact that the Humminbird pushes me to the 9" unit, I should look more at Lowrance.
I have an old Lowrance structurescan on the boat and works well.

I also don't know how boat roll and pitch affects the data. Does Reefmaster have an algorithm for this? I don't know ith eth sonar units compensate for this, but i would have a deed for this too.

Thanks

geoconnect60 wrote:
You need to be aware that, even if you feed cm precision RTK into your unit, you won't get a log file with this level of accuracy. Both Humminbird and Lowrance store locations to an accuracy of around 1m - this is due to the file format, and there is no way to get around it. This means that track paths need further smoothing (with some inevitable loss of accuracy) before they can be used for sidescan mosaic. Neither format stores absolute times either - they both store a millisecond offset from the start of the log, and with Lowrance there isn't a reliable way to determine the absolute start time.
I would strongly suggest looking into setting up independent logging of your GPS data and postprocessing to combine the GPS data with the sonar log - functions to handle this should be available within RM by the end of the year.
Although we don't use pitch and roll yet, we are looking into it and, again, you would need independently logged files to take advantage of this as there are no corresponding fields within the current Lowrance of HB log files.

Simrad now uses heavecompensation in their NSS and S2009 as long as you have a sensor like P-9. But I don`t know if the sonarlog reflects this.

Hi, all,
Looking to do some of my own mapping in the near future with RM. First I need to pick up a durable plotter/ff for here in Pacific Costa Rica. I do a lot of trolling with my Hobie TI here and the water can get deep fast. My heart is set on a Lowrance unit,, don't need any mapping up front, can use my tablet with navionics boating to begin with. I'm thinking the Elite-7 TI fits my needs, but I have some concerns. Often times, being so close to the water, I get a lot of inadvertent ocean spray, so I really need to cover my plotter with a Taylor Made cover (see thru). Problem is, the Elite-7 TI says that it can easily overheat without proper ventilation. On a call to a tech at Lowrance they said it was because of the TotalScan transcducer. I suppose that means that the head unit works much harder for this transducer.
I could go with a 50/200khz HDI ducer instead, which would be better for deeper water reads, not that I fish them directly other than surface/downrigger. This ducer would keep the head unit cooler for covering. But will I want that structure scan or side scan data I would be missing???

EDIT: I just remembered, even if I could go with the TotalScan transducer, I don't have a good way to mount this duce on a non Lowrance ready Hobie. Another issue is that the Elite-7 TI is not fully non touch capable, not sure how this would work. Really wanted the Elite-7 TI for the faster processor speed and brighter screen over a Hook. Gen 3??? gulp!!

Thanks CR Yaker

Lowrance HDS Gen 3 and Simrad NSS EVO 2 both offer the same options as far as Reefmaster goes, and have multi-touch (buttons and touch) as well as better screen then the Elite Ti which has the same screen ad the older HDS Gen 2 Touch.

The NSS should be going on sale shortly, I expect it to be replaced this winter.

I would not worry about this to much though. :) The Elite will take a lot a spray and combined with 50/200/455/800-HDI it is a great took for fishing. Even I have bought one for my small boat. :D

Thanks Colibri,
I've narrowed it down to the Simrad GO7 XSE or Elite-7 TI. I do not need any motor, networking functions.

Which of these two better serves my needs with RM, salt water abuse, bright screen in direct sunlight?

I think I figured out how to mount the totalscan transducer. Which transducer is better for fishing/mapping, totalscan or HDI 50/200khz?

Realistically I won't be fishing below 150' water column. Sometimes traveling as deep as 1000' to 1500'.

So far, I like the Elite TI better for it's mount.
I like the Simrad better for it's price, looks, touchscreen capabilities and warranty.

Thank you
CR Yaker

Does the Simrad have StructureScan? Well worth having, especially if you are going to run the TotalScan transducer. I have an Elite 7 Ti set up on my kayak and it's perfect on there, and mounts really well with a RAM ball in the quick release bracket. I haven't really got it very wet yet, so I can't comment on that aspect - I assume the unit should be able to handle it, although it should be noted that unused rear connections don't come with covers. Mounting the TS transducer on a kayak is a bit of a pain as you can't run it in-hull or use the transducer pocket underneath the hull. As far as mapping/logging goes, the unit works as well as any other and the touch screen works very well.

Here's a few pics of my install on a Hobie Revolution:

Having just re-read your post, you indicate that you won't be fishing shallower than 150' ? I read that the wrong way round initially - if that is the case, then sidescan won't be much use to you so you might be better off looking at a good 2D transducer that you can mount in-hull. I don't this DS will do much for you either in 1000' of water.

Thanks Matt,
Yes, I meant no deeper than 150', fishing, travel through deeper water. Your mount looks good. I plan on doing it through the scupper hole in the back of my Tandem Island. It isn't going to be pretty either way, but it should work well.
Received some more information on screen brightness. The Simrad is 1200 nits and supposedly the Elite TI is similar as the Gen2 which is 1200 nits. Suggestion was that because of the sensitivity/multi touch of the Simrad touch screen that it might not do as well in salt water spray. Thus chalk one up for the Lowrance.
Looks like the Lowrance Elite-7 TI will be the way to go. I don't plan on the unit lasting more than 4 years from the abuse I'll give it, so extended warranty. I'll be glad if I can get 2 seasons out of it.

GO XSE and Elite Ti are more or less the same unit. GO has full on Touch with "pinch to zoom", Elite Ti has simple one-finger touch and a few buttons. GO supports Simrad Forwardscan, Elite supports Motorguide Xi5. Both can use TotalScan for Structurescan+2D, the sonar is the same in both.

I belive Totalscan would be ideal for your use, as long as you can mount it in a good way. 50/200/455/800-HDI will give more precise depth, simply because it has a less wide coneangle at 200 kHz then Totalscan (half of the coneangle). But in your depths that difference will be so small you will not even notice it.