This screenshot is from a Raymarine Axiom Pro running
a Raymarine R111 in-hull transducer, with all settings
on Auto. It shows the grounds off Sydney known as
‘Brown’s Mountain’ and illustrates how well the Low CHIRP
setting can show the bottom in 800m even while the
boat is travelling at trolling speed. The skipper has put a
waypoint marker on the 450m ledge just before the peak,
making it easy to return to for a swordfishing drift.
Another view of Brown’s Mountain off Sydney on the
Raymarine Axiom Pro, this time with a split-screen
showing the difference in the sounder’s readings with
Medium CHIRP frequencies used on the left, and Low
CHIRP frequencies on the right. The Low CHIRP provides
a very clear and distinct view of the bottom but lacks the
subtlety of the Medium setting, which shows a school of
fish sitting right on top of the pinnacle.
bluewatermag.com.au 43Sounding Out The Final Frontier