Cruising Helmsman – June 2017

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Cruising Helmsman June 2017

ABOVE: Hollow

axle to allow

cables routed

above the

headlining to pass

through.

RIGHT: Mk.3

mount, note

retaining nuts and

rotation limiter.

MARK 2: HOLLOW PIVOT

However, the chartplotter eventually failed

irreparably due to corrosion between

the power socket, surface mounted onto

the main circuit board and incompatible

metal pins in the sounder adapter cable.

To avoid replacing the through-hull

transducer and its tortuous cabling, I

bought a new seven inch model of the same

brand, which also came with a skimmer

transducer but had a larger sounder socket

that did not require the cable adapter.

This unit had a conventional tilting

yoke mounting bracket and installing it

provided the opportunity to incorporate

an azimuth pivot, drawing on my earlier

experiences with our below-decks

electronics, see later explanation. This

Mk.2 arrangement allowed the display

to be tilted up and down, also rotated to

either side so it could be visible to crew

seated under the dodger or standing in the

companionway.

The cabling is fed through a hollow

pivot and a small toggle-stop prevents the

mount and cables from being rotated more

than +/-190 degrees.

This proved a great success on our next

cruise around Tasmania and I seriously

suggest that anyone considering mounting

a cockpit chartplotter in a cruising yacht

investigate a swivelling option.

Unlike a harbour sailor or a racing

yacht, a cruiser is often under autopilot or

windvane steering, sometimes for hours

or even days on end. Even watchkeeping

crew are likely to spend much of their time

under the shelter of a dodger or braced on

one side or other of the cockpit where they

cannot easily see a fixed f lush mounted

display at the helm. Being able to glance

up is certainly more convenient than

having to move around behind the wheel

and allows for more continuous situation

awareness.

MARK 3: ADDING RADIO

Our shift to using a cockpit unit meant

that our original chartplotter, mounted

down below, became the backup and was

usually switched off.

This unit was a VHF combo, I had

installed its radio’s optional remote

microphone and speaker under the

dodger. So regrettably, this too was no

longer usually switched on and we had

PRACTICAL

ELECTRONICS

SCHEMATIC OF MK.2 AND #3 PIVOTING DESIGN

Section view of hollow axle concept

3mm aluminium sheet secured

between dodger frames

Swivelling plastic base onto which

equipent brackets are bolted

60mm x 6 wall aluminium

tube welded to sheet

3mm studs set into tube end, with

washers and Nyloc nuts (6 off)

3mm thick aluminium retaining ring

Dodger

headlining

Plastic spacer ring

Plastic ring

Power, data,

sounder, and

antenae cables

feed through

hollow axle