Cruising World – May 2018

BOATS & GEAR

may 2018

cruisingworld.com

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today are rapidly moving to

solid-state radars that use gal-

lium nitride power amplifi ers,

which broadcast their signals

on X-band frequencies (9.3 to

9.5 GHz) using pulse-compres-

sion schemes that enable Dop-

pler processing. That is, these

new radars use less power, and

Doppler processing allows

them to identify and assess tar-

gets that may or may not be-

come threats. Vessels travel-

ing on a collision course will

typically be painted one col-

or (often red); nonthreatening

targets are painted a different

color (such as green); and sta-

tionary objects and landmass-

es are usually presented as

standard radar imagery, giving

operators at-a-glance situation-

al awareness. This awareness is

further enhanced by features

such as automatic radar plot-

ting aid and mini- automatic

radar plotting aid, which auto-

matically or manually track ves-

sels, giving a skipper real-time

speed, bearing and closest-

point-of- approach information.

Best yet, gallium nitride power

amplifi ers are now less expen-

sive to manufacture than mag-

netrons, representing a rare

case of newer and signifi cantly

better technology costing the

same or less than previous-gen-

eration equipment.

Thermal-Imaging Cameras

When it comes to nav-

station cool, it’s tough to top

thermal-imaging cameras,

which use highly sensitive mi-

crobolometer sensors to detect

minute thermal differences

(one-twentieth of a degree Cel-

sius) between an object and its

surroundings. These highly ca-

pable cameras are equally ad-

ept in the glaring noonday sun

as they are during the graveyard

watch, and they are available in

either handheld or fi xed-mount

models, the latter of which

are controlled by a networked

chart plotter and can typically

pan and tilt. The vast majority

of thermal-imaging cameras for

marine use also offer the ability

to zoom, but just as with digi-

tal photography, optical zooms

provide far better image reso-

lution than their digital coun-

terparts.

Virtually all thermal-imaging

cameras offer a variety of col-

or palettes, which are useful in

different atmospheric condi-

tions and for spotting different

things. Some systems even can

detect, assess and track targets.

Historically, thermal imag-

ers were the trappings of large

poweryachts. However, this

is rapidly changing thanks to

the plummeting prices of both

handheld and fi xed-mount

cameras.

Weather-Routing Software

One of the most dramatic

impacts that today’s informa-

tion age has had on cruisers

is the ability to take high-

resolution weather GRIB

fi les and import them into

computer-based weather-

routing software. There are

multiple products available,

so you should be able to fi nd

software that’s compatible

with Linux, Windows or iOS

platforms. These weather rout-

ers use a sailboat’s polars, or

performance-characteristic

metrics, to determine the saf-

est and most effi cient course

to your next destination, using

user-selected parameters such

as maximum (or minimum)

forecast wind speeds or wave

heights, both of which can af-

fect crew comfort. Weath-

er-routing software can also be

used to consider tide and cur-

rent information, allowing us-

ers to play with their optimal

departure times in order to

make landfall at, say, fi rst light

or during a particular tide cy-

cle, when draft might be criti-

cal. As with all forecast-based

decision making — whether

done by skipper or machine —

the more up-to-date the data,

the higher the chances that its

forecast outcome will be ac-

curate, so while cruisers can

download a GRIB fi le before

setting sail, they will likely be

far better served if they can

download fresh GRIB fi les en

route (see “Communications,”

above).

Wireless Connectivity

One of the more useful recent

evolutions in chart plotter

technology has been the

now-universal adoption of

built-in Wi-Fi connectivity,

allowing users to share net-

worked instrumentation and

NMEA data with third-party

devices such as smartphones

or tablets.

That fancy tablet that

Rudiger had aboard Avanti?

Assuming you have a Wi-Fi-

enabled plotter (or an onboard

wireless local area network),

you can have access to the

same on-deck situational

awareness that he enjoyed for

the price of an iPad, a naviga-

tion app and a waterproof case.

In other words, for pennies on

the dollar compared to Rudi-

ger’s kit.

This same wireless fl exibili-

ty allows users to fully leverage

wearable technology, such as

sailing-specifi c watches and

eyeglass-style head-up dis-

plays, while also allowing any

smartphone or tablet to stand

double watch as a chart plotter

repeater, the latter of which

saves the expense of having to

spec extra chart plotters, say,

for the helm or nav station be-

low. Additionally, some manu-

facturers are now offering Wi-

Fi-enabled radars that swap

their hard-wired data cable in

favor of a wireless connection

with a plotter or smart device,

a technology that also helps

reduce weight aloft.

David Schmidt is CW’s

electronics editor.

Onboard data gets displayed in multiple ways. From left: Wind and sailing information is overlaid on B&G’s Vulcan 7;

weather is displayed on a Raymarine plotter running Lighthouse cartography; and critical navigation information appears

on Garmin’s quatix 5 sailing-specifi c watch.

What’s Old Is New

GPS enables ultraprecise

navigation. However, the

system relies on satellites

that are vulnerable to attack

and receivers that can be

jammed or spoofed. As a

result, the U.S. Navy began

re-implementing celestial

navigation as part of its

offi cer-training curriculum

several years ago. While

cruising sailors aren’t

likely the targets of state-

sanctioned GPS attacks,

our receivers use some

of the same target-worthy

infrastructure that the

military employs. Moreover,

lightning strikes or other

calamities can blind a yacht.

Careful navigators, therefore,

maintain accurate logbooks

and practice dead reckoning,

while shrewd skippers carry

a sextant and related kit for

serious bluewater passages.

Additionally, the advent of

modern celestial calculators

(both stand-alone and

app-based) and celestial-

navigation software ease the

burdens and computations

associated with gleaning

one’s positions from the

heavens.

PHOTOS COURTESY OF THE MANUFACTURERS