wild guide: sound underwater
TEST 17 subject: OUTBOARD MOTOR
- trolling speed
The next test will certainly interest you, as
it directly refers to outboard motors. On
my boat, I have a very quiet 225CV. This
time, we did our testing at a trolling speed.
Daniel told me that when he climbed back
to the surface he could hear mechanical
parts turning and a sharp, continuous
sound. It is unthinkable to believe it when
you learn that in 5 and 10 feet deep the note
is 6 out of 10, then 5 out of 10 in 20 feet and
it goes up to 6 out of 10 in 20 feet directly
above Daniel. It is almost unimaginable
to know that fish are baiting behind our
boats. It would then be advisable to fish
very far behind our boat or to use surface
drifters.
TEST 15 subject: TROLLING MOTOR
- 20% power
Several boats are equipped with an electric
motor. This is fantastic for moving around
with no fuss. My boat was equipped with
a bow mounted Motor Guide Xi5 with
80 pounds of thrust. My 19’10” boat is
relatively heavy, which requires a lot more
power unlike a smaller boat. As part of this
test, I passed near the diver, not far from
him at a continuous speed equivalent to
20% of the maximum power. The diver
heard a slight, continuous whirring. His
score card indicated in the usual order of
marks of 2, 1.5 and 1 out of 10. TEST 16
subject: TROLLING MOTOR - 80% power
We did exactly the same scenario as test
15, but at a speed equivalent to 80% of the
maximum power. Daniel then perceived a
sharper sound. The notes then increased
considerably, reaching 4/10 in 5 feet of
depth, 3/10 in 10 and 2 in 10 in 20 feet
always in angle of 45 degrees with the
craft. When I passed directly over him, the
rating is raised to 3 out of 10. It should be
understood that Motor Guide engines are
recognized as being very quiet. Imagine if
you opt for an engine that is not working
properly or that is just noisier.
5 FEET 5 FEET
10 FEET 10 FEET
20 FEET 20 FEET
20 FEET 20 FEET
TEST 18 subject: OUTBOARD MOTOR
- 25 km/hr
We have done the same operations again,
but this time I have been driving at medium
speed at about 25 km/hour. In many of
my texts, I urge you to stop the outboard
motor at least 300 meters from the site
you want to operate, with the ultimate goal
of approaching it gently so as not to scare
anyone who swims. The score obtained in
all situations was 9/10. The very strident
sound occasioned resembles a powerful
rumbling with several vibrations.
5 FEET
10 FEET
5 FEET
20 FEET
10 FEET
20 FEET
20 FEET
20 FEET
49 Wild Guide
. Fall 2017