Humminbird HELIX 5 against Lowrance Eagle 7: power against imaging

Each one publishes what the other leaves blank

This is the unusual thing about this pair, and it shapes the whole comparison. Humminbird publishes transmit power and maximum depth. Lowrance publishes brightness and imaging range. Neither publishes the other’s figures.

That is not a trick. It reflects what each maker thinks the buyer cares about, and it means a straight specification-for-specification comparison is impossible. What follows compares what is actually stated.

The published figure that surprises people

The 5 in unit draws more current than the 7 in one. 615 mA against 550 mA, both published.

Screen area is not the only thing consuming power — transmit power is, and the HELIX 5 is pushing 500 W RMS through its transducer. If you assumed the smaller unit was the frugal one because every other piece of electronics works that way, the spec sheet says otherwise.

It is a small difference in absolute terms. It is a useful reminder that on fish finders you should read the published draw rather than infer it from the screen size, particularly if you are running off the sort of small battery our battery page covers.

Imaging or power: which absence hurts more

The honest way to choose here is to work out which missing capability you would actually notice.

You would notice the missing imaging if you fish reservoirs with brush piles, laydowns and standing timber, or if you like to idle a flat and build a picture before you cast. This is most bass fishing on most impoundments, and it is why imaging sells.

You would notice the missing power if you fish deep, cold, clear lakes where the fish sit at 60 ft and the return is faint, or stained water where a weak signal disappears into noise. Trout and lake-trout water is the clearest case.

You would notice the missing AutoChart Live if your water is not well-surveyed. A farm pond, a small state lake, a new reservoir — none of those are in C-MAP’s 17,000 lakes in any useful detail, and drawing your own contours is the only way to get them.

The screen comparison is not what it looks like

Both publish 800 x 480. One spreads it over 5 in, the other over 7 in.

That means the Eagle 7 shows exactly the same amount of information, just larger. It is easier to read at a glance and easier to read at distance, and it is not more detailed. If you were hoping the bigger screen would resolve finer sonar detail, it will not.

It does make split screens usable. Running CHIRP alongside DownScan on a 5 in panel at this resolution leaves each pane very small; on 7 in it is workable. That is a real argument for the Lowrance if you intend to run two views at once.

Which to buy

HELIX 5 for deep or stained water, for anyone who wants to map their own lake, and for anyone whose budget stops well short of the Lowrance. It is the stronger sonar on the published numbers.

Eagle 7 for reservoir and impoundment fishing where structure is the target, for anyone who wants a bright 7 in screen, and for anyone who will use SideScan rather than merely own it.

If imaging is the reason you are buying, our under $500 page and main roundup both cover the step up from here.