A chartplotter fishfinder combination unit offers powerboaters, sailors, and fisherman a number of advantages over purchasing a separate chartplotter and sounder to meet their marine electronics needs.
First off, youll save a bundle of cash when going with a combo because youll only be paying for one display screen, one component chassis, and one case.
You will also be significantly simplifying your life when it comes time to install the display and wire things up.
The operational learning curve will be reduced too because youll only have to learn how to operate one unit instead of two new pieces of equipment.
One frequently mentioned downside of a combination unit is the fact that you are now putting all your marine electronics eggs in one basket.
For most boaters, this is not that much of a problem since outright failure is fairly rare. However, you should still have a means to navigate to a safe haven if the unit does fail.
The most important factor when choosing a chartplotter fishfinder combo is the display screen. We always opt for the largest highest-resolution screen we can afford.
Big screens offer more details that are easier to read on a fast moving bouncing boat. A very common scenario today is for even small screen units to carry fairly high pixel resolution.
For instance a couple new 5-inch screens weve tested have resolutions of over 150 pixels per running inch. A screen like that will be capable of displaying incredible detail, but must be viewed from close range.
Look for a chartplotter fishfinder combo that meets your connectivity needs. If you have an older boat that is not likely to get rewired with a NMEA 2000 network backbone you certainly wont need to worry out having that capability in the chartplotter you buy.
On a new boat where its possible the network backbone was factory installed youll be giving yourself a lot of options for future upgrades if you buy an N2K compliant combo unit and connect it to the network.
A number of newer chartplotter fishfinder units are capable of displaying AIS targets when connected to a receiver. This information is generally passed back and forth using a NMEA 0183-HS network. This is a 38400 baud network that is not compatible with the older slower 4800 baud NMEA 0183 system.
If you need either of these types of data to talk to other gear already on your boat check to make sure the unit you are buying is compliant.
Cartography is another item to consider prior to purchase of any chartplotter fishfinder combo unit. You may already own or be able to trade up on a certain brand of chart card.
If so, it might be in your best interest to choose a plotter brand that uses your preferred cartography.
Sometimes though its cheaper and easier to start from scratch and pick the system you like then add the chart cards as needed.
Today many chartplotters are available with top notch pre-loaded cartography for very little additional money.
If you rely on your sounder to supply important depth and bottom composition information, or even more importantly if you fish, your needs will be best served by choosing a combo where the maker has properly integrated a capable fishfinder.
If you always operate in water less than 300 feet deep you can stick to units with lower output power and a single frequency transducer.
Look for a unit with at least 500 watts of power and the ability to use a dual frequency transducer if you regularly operate in the deep water arena.
Doing so will allow you to use the high frequency, normally 200 kHz, to read a wide swath in shallow water and provide intimate details of the bottom. Using the low frequency, typically 50 kHz, will let you probe the depths with ease.
Typically you can expect to read bottom in a minimum of about 2 feet of water with a high frequency transducer and about 5 feet when using the low frequency.
Maximum depth capabilities with 500 watts of output power would be about 500 feet when using 200 kHz and somewhere between 1000 and 2000 feet using 50 kHz.
Going with a more powerful 1000 watt sounder and transducer could add a couple hundred feet to the maximum depth with high frequency and over 1000 additional feet using low frequency.
Most all combo sounders will have water temperature capabilities. This can be valuable information when trying to determine whether youre riding a current channel in an otherwise open sea. Fishermen frequently use slight variations in temperature to find pockets of water that might hold large pelagic species like marlin.
Another transducer add-on you see is the speed wheel. This paddle wheel is supposed to supply water speed to the display unit. In our experience, these paddle wheel units are notoriously inaccurate and prone to failure. Wed choose a transducer without this option whenever possible.