Finding fish without a fish finder is like wearing a blindfold and trying to find that one cold beer in a rotomolded cooler full of empties.
You know there is one around somewhere but you just have to keep diving in to try and locate it.
I remember when I used to go deep-sea fishing in an old canoe with a 25HP engine with nothing but a few oars and a mobile phone for safety (not recommended).
The only way I could tell where I was, was by looking at landmarks and I could guess the depth based on how far from the reef I was, and if I could see the bottom, I was way too shallow. It was awful.
Using a Fishfinder
The day I got a fish finder like the Humminbird 999ci HD SI my life changed. I could focus on fishing instead of checking where I was.
I knew the depth, I found pinnacles and fishy areas, areas that I’d only have ever stumbled upon by mistake and never found again before I owned a fish finder.
My catch rate went through the roof, my smile grew a few inches, and it was all thanks to fish finders like the Humminbird 999ci HD SI.
Join me as I review humminbird 999CI so you don’t waste time scanning the internet…
In this article...
Things to consider before buying a Humminbird 999ci HD SI
Does the Humminbird 999ci HD SI have GPS?
Yes, these fish finders come with an advanced GPS system that uses GPS technology that provides a means for you to know your accurate global position within 20 meters.
You can use the advanced GPS system and GPS technology to mark over 3000 waypoints, save 45 routes, and save over 50 tracks.
How deep can the Humminbird 999ci HD SI read?
These fish finders have a maximum depth of 1500ft which is more than enough for any boat fishing in a lake and in the ocean.
Does the Humminbird 999ci HD SI have a side imaging feature?
Yes, this fish finder will give a high definition side image of 150ft of either side of your boat so you can see if there are any fish you should cast to or turn the boat and try to troll your bait’s past.
Can you add charts to the Humminbird 999ci HD SI?
Yes, the unit has two sd card slots when you can add SD cards with Navionics and LakeMaster charts.
Which high-speed transducer works with the Humminbird 999ci HD si and does it come with the 999ci HD si combo?
The high-speed transducer that works with these units is the XHS 9 HDSI 180 T Humminbird transducer and it comes as standard with the 999ci HD si combo.
What’s the battery life like?
The battery life should be never-ending as you should power the unit via a 12-volt that should be recharged by your engines while you use it.
The unit does have a high power output of 1000 watts RMS though, so if your battery isn’t being charged it’ll drain within 2 hours, especially if you’re using the unit on the highest power rating.
Who should buy one of these units?
If you own a boat with onboard power then the Humminbird 999ci HD si combo is a great fish finder for you.
It got everything from high definition sonar images to GPS and charts, everything you need for fish finding with ease in lakes and the ocean.
Check out the Humminbird 999 HD SI in action…
Who shouldn’t buy one of these units?
If you’re looking for something portable, own a boat without onboard power or it’s a little small with minimal console space, then the Humminbird 999ci HD si combo might be too powerful and too large a unit for your needs.
You’d be better off going for a smaller model with a lower power output like the Humminbird Helix 5 or Garmin Striker 4 unit.
Everything you need for fish finding with ease in lakes and the ocean, from high definition sonar images to GPS and charts.
Humminbird 999ci HD Si Combo Review Overview
The Humminbird 999ci HD si combo ticks all the boxes when it comes to the features a fish finder can give you.
With this unit on your boat, you’ll be able to navigate around the world using the charts and GPS, see all the fish on the way with the sonar features, and you can even link it to radar and autopilot systems to help make your journey easier.
What comes with the fish finder?
When you order a Humminbird 999ci fish finder, you’re getting a high definition display screen, a high-speed transducer, mounting brackets for both, plus all the cables you need to power and connect them.
The day it arrives, all you’ll need are a drill and some screws from the hardware store to install it.
- Large display with an 8-inch full-color high definition screen
- Sunlight readable LCD screen
- Excellent sonar features including Down Imaging and Side Imaging
- Control image details with SwitchFire Sonar
- Sonar recording so you can review it later
- Accurate GPS with the ability to save 45 routes, mark waypoints, and more
- User-friendly and simple to understand once you read the manual
- Quick and easy installation
- Comes with a transducer included
- Two card slots for MicroSD memory expansion
- Able to add extras like autopilot, radar, and more
- It’s quite an expensive unit
- It’s an old version and is discontinued by Humminbird
- There is no Bluetooth or wireless networking
- It’ll drain a 12-volt battery in 2 hours if it’s not being recharged as it should
What features does the fish finder have and why are they useful?
How good is the display?
This fish finder comes with an 8-inch screen which is quite a large display making it easier to pick up all the little details on the sonar images.
It also makes it easier when you use split-screen mode to view multiple features.
The screen is HD on this model and gives exceptional image clarity and with a 480v x 800h pixel resolution, you can see it in all light conditions, even with polarized sunglasses in direct sunlight.
The screen unit is shock-absorbing to protect it from any engine vibrations and is waterproof to IPX7.
This means it can be submerged for 30 minutes at a depth of 1 meter, so it’ll handle rain, splashes, and even a torrential downpour with ease.
Ease Of Use
Next to the screen, you’ll find the control keypad that you navigate around the fish finder with.
There is a shortcut button to most key features like sonar, charts, and GPS for quick access, plus simple to use mark, go to, and view buttons that make using this unit easy and efficient.
What are the sonar features and what do they show you?
Dual Beam Plus
The most basic sonar feature on this fish finder is Dual Beam Plus.
It works by sending out two sonar beams, one wide-angled with a large coverage and one narrow angled for detail.
Together they give you a fully detailed picture of the entire water column down to 1500ft.
You’ll be able to see the bottom, bottom structure, and any fish or debris between your hull, the sea, or lake floor.
It’s the sonar feature a fisherman would use the most while trolling or looking for a good fishing spot as it covers the entire water column in detail.
Down Imaging Sonar
Down Imaging uses a more intense sonar beam with higher wave frequencies that pick up a lot of detail.
You’d use Down Imaging when you have found something like a wreck or a brush pile you want to see in more detail than dual-beam can offer.
You’ll be able to see exactly what the structure is, what depth it’s at, and if and where any fish are holding on it.
Down Imaging on this unit only works down to 150ft, so anything you’re looking at will have to be within 150ft from the transducer.
Side Imaging works the same way as Down Imaging except it sends its sonar beams to the side to provide a means to see any fish you might have missed up to 150ft on either side of you.
The side imaging on this Humminbird is excellent and provides amazing clarity when compared to the side imaging on equivalent fish finders.
You’ll see shoals of baitfish, lone predators, and even specs of seaweed; it’s so accurate.
SwitchFire is a feature unique to Humminbird and you can use it alongside all the sonar functions.
It lets you choose how much detail you want to see on the screen and quite often the minimum is better.
Clutter, such as debris in the water can take over a sonar image and make it hard to know what you’re seeing on the screen as the clutter can overshadow fish arcs.
Using SwitchFire you can tailor the amount of detail on the screen so you can hone in your preferred targets, like large fish or shoals of baitfish.
Sonar Record & Review
At the press of a button, you can tell the fish finder to start recording your sonar data so you can review it on the screen later on.
This is a useful tool as it allows you to go back and look at particularly fishy areas that you don’t have time to analyze in the moment and understand why the fish chose to be there.
You can also mark a waypoint via this feature, so if you didn’t hit mark at the time because you were too busy catching fish, if you recorded it, you can still go back and save the spot to return to it next time.
GPS, Charts, and Navigation – Where can they take you?
The GPS on this Humminbird is accurate to 20 meters and fixes your position within 30 seconds of being turned on.
Once it has a fix it’ll follow you, tell you your boat speed, create tracks of where you’ve been, let you plan routes, and mark over 3000 waypoints.
You can use it anywhere in the world, and it has the power to navigate you safely to anywhere in the world you want to go.
This unit comes with the Humminbird Basemap preloaded which gives you a pretty good map including depth, marinas, hazards, and more for US lakes and the coast.
You can also upgrade to other charts if you prefer and the fish finder is compatible with both Navionics and Lake Master.
Finders and Networking
When it comes to networking there is no wifi or Bluetooth on these finders but it does have NMEA and ethernet ports.
These ports allow you to network your engines so you can see data like fuel consumption, RPM, hours, and more.
The ethernet ports let you add on extra features to the unit like autopilot, radar, and more. This means you can slowly build up your vessel electronics bit by bit using the 999ci HD si unit as a base to expand from.
Is there a better fish finder out there for the money?
The Garmin ECHOMAP UHD 74SV is more affordable and has better features than the Humminbird, here are the differences.
- The Garmin has Wifi and mirrors on your smartphone for viewing and remote control
- You can save 5000 waypoints on the Garmin instead of 3000 on the Humminbird
- The Garmin is more affordable by a third
- The Garmin has a touchscreen
- The Garmin scans deeper in every sonar feature
- The Garmin has CHIRP sonar, the Humminbird does not
- The Humminbird screen is 1-inch bigger than the Garmin
- The Garmin has a self-mapping feature
The Garmin ECHOMAP UHD 74SV is a better fish finder than the Humminbird with more and better features than the Humminbird.
Save some money and get the ECHOMAP UHD 74SV instead.
The Helix 7 is one-third of the price of the 999ci HD si and has almost all the same functions, here are the differences.
- There are no networking capabilities on the Helix 7.
- The Helix 7 has no side imaging
- The Helix 7 has CHIRP
- The Helix 7 has better down imaging in terms of range and accuracy
- The Helix 7 creates maps for you
Overall you’re paying three times as much for the 999ci HD si for fewer features but you do get side imaging.
Overall the Helix 7 is better for the money so if you want to save some cash go with that one.
A much more affordable option than the Humminbird, by almost two-thirds and it has some better features but is missing some too.
The Striker Vivid 7sv is a much more affordable option than the Humminbird, by almost two-thirds and it has some better features but is missing some too. Here are the differences.
- The Garmin doesn’t let you use charts
- There are no NMEA networking ports on the Garmin
- You can’t expand and add extras like radar and autopilot
- The Garmin has a smaller screen by 1 inch
- There is wifi on the Garmin for smartphone integration
- The Garmin self-maps unlike the Humminbird
- The Garmin has CHIRP sonar, the Humminbird does not
If you’re on a budget and happy to use sonar and build your own maps, the Garmin is the better unit for you plus you’ll get Wifi for smartphone notifications.
Thanks for reading my 999ci HD si review, I hope you enjoyed it.
The Humminbird 999ci HD si is a great fishfinder and gives you some of the most accurate sonar images around, plus you can navigate around the world with it using the GPS and compatible charts.
With a fishfinder like this on your vessel, there is nothing to stop you.
If you’re looking for more options, you can also search on this site for other fish finders. I’ve reviewed almost every fish finder available on the market right now, including the Helix 9 series and Lowrance HDS series.