Owner`s manual

MAY 2011 31PRACTICAL SAILOR
pre-race maneuvers to dene the starting
line. e buttons are clearly labeled with
a triangle on the le side (pressed when
alongside the pin end of the start line),
and a square right side (pressed when
alongside the boat side of the start line).
Once the start line is defined, the
ProStart will display distance to line
within .75 to 3 meters, depending on
the location of satellites in view. The
distance-to-line is displayed on the
bottom half of a split screen, with the
time-to-start displayed on the top half.
Finally, at the bottom of the unit is a
clearly labeled button for “Gun.” Press it,
and the countdown timer begins. Once
the race starts, the unit automatically
switches into race mode and the user
can make use of the tactical compass, as
well as monitor speed over ground and
course over ground to check current.
The windshift indicator, like the
RockBox’s knock-li graph, graphical-
ly represents subtle shis in the course
steered. Unlike the RockBox, however,
you cannot set your own reference head-
ing. Instead, the ProStart uses an algo-
rithm to establish the reference heading.
To acquire the reference heading,
the unit constantly tracks a 20-second
moving average of your heading. When
your heading is within 10 degrees of the
20-second average for 10 consecutive sec-
onds, the device sets this as the reference
heading. When you are holding the refer-
ence heading, a single bar appears at the
12 o’clock position on the display. Any
deviation to port or starboard from the
reference heading is indicated by addi-
tional corresponding bars. Each bar rep-
resents 2.5 degrees. If you tack, jibe, or
your heading deviates from the reference
heading by more than 45 degrees, the bar
graph automatically resets and the device
waits until your heading is steady again
before setting your new course as the bar
graph’s reference heading.
Adjusting the compass for local
variation, and setting bow offset (to
compensate for any distance from the
actual bow of the boat and where the
unit is mounted) are the only two set-
up actions that require extra guidance.
Both of these are described in a short
YouTube video on the website. It also is
in the owner’s manual.
e Velocitek’s GPS chip has a fast-
er speed solution update rate than the
RockBox. Testers noted the speed and
heading readings seemed more stable
than those in the RockBox, although
this was most obvious when the units
were stationary. e Rockbox would oc-
casionally ash speeds of a few-tenths of
a knot while the Velocitek would read a
steady “0.0.” In both units, the distance-
to-line function serves as a good guide for
timing your run to the line, but should
not be regarded as a precise indicator of
distance, according to our test ndings.
To analyze the data, testers used a trial
version of Velocitek’s SpeedPlay soware
($49) to replay logged data. e soware
allows the user to easily drag and drop
race marks on plotted routes, and the
track can be exported in common for-
mats (KML and GPX) for use with chart-
ing soware or mapping tools like Google
Earth. Velocitek’s website also has links
to a bundled third-party program, GPS
Action Replay, for further analysis, but
the interface is clunky and the graphics
are uninspiring. ere are several other
racing soware programs for analyzing
data, and PS would be interested in hear-
ing feedback from readers on the perfor-
mance of these programs’ soware.
Testers did not have any problem in-
stalling either Velocitek soware pro-
grams, both of which come with instal-
lation wizards.
Bottom line: Well-designed and
easy to install and use, the ProStart is
a clear winner in this category and a
PS Best Choice. Although it lacks many
of the extras found in the RockBox, it
gives racing sailors any easy-to-use tool
that gives them a technical edge over
other sailors and an ability to replay,
analyze, and share race data. Small-
boat sailors looking for a fun device
to track speed and improve their skills
will also appreciate its portability.
conclusion
Anyone considering either of these de-
vices should ask themselves how they
intend to use them. e key feature in
both the RockBox and the Pro-Start is
the large-digit display, which gives the
helmsman instant feedback to subtle
course or sail trim changes. Although
both are designed primarily as around-
the-buoy performance and training
tools, the RockBox’s waypoint func-
tions and backlighting can serve just
as well on longer races or even while
passagemaking.
e Velocitek was much easier to use
than the RockBox, but part of that is a
trade-o for having the remote—a nice
feature for a single-hander. Velocitek’s
solution is two units mounted on either
side of the boom, an expensive option
that some multihull racers are using.
In our view, the RockBox has its
niche, but the ProStart is the smarter
choice for most racing sailors. It’s easy
to use and delivers the data needed to
nail a start or gain that extra tenth of
a knot.
Velocitek, 800/693-1610,
www.velocitek.com
rockbox, www.rockcitymarine.com
contacts
electronics
Speed data appears
digitally and graphically
in one of the several views
available in the RockBox
graphing mode (left). The
Velocitek ProStart (right) in
start mode shows time until
start and distance to line.
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