Nigel Calder Answers Question - Ask Sail Page 2 - Sail Magazine

Nigel Calder Answers Question - Ask Sail Page 2

THE EXPERTSNigel Calder is an expert on boat systems and diesel engines. Don Casey has written many books and articles on marine maintenance and repair. Tim Bartlett is a former Royal Navy officer who is an expert in radar and electronics systems. Gordon West is a communications expert and a specialist in radio communications.DIRTY GROUND
Author:
Publish date:
saip_0909_05_z+answers_question+tim

COMPASS TRUISM

Is it all right to use magnetic headings on my chartplotter to adjust a new compass?

KARL WESTMAN, OCEAN CITY, NEW JERSEY

TIM BARTLETT REPLIES:

In theory, definitely not. But in practice I'd have to give you a very guarded "maybe." The problem, of course, is that your heading is the direction your boat is pointing in. Your chartplotter/GPS unit cannot know this. It only knows the direction the boat is moving, known as your "track" or "course over ground."

saip_0909_06_z+answers_question+bearings

And there can be a big difference. For example, if you are doing 6 knots with a 3-knot current on your beam, there's a difference of almost 30 degrees between your heading and your track. But if you should be lucky enough to have a perfectly calm day and there is no tide or current to affect the boat's course over the ground, the track shown by your chartplotter should be the same as your compass heading if the compass is adjusted properly.

A good way to check your compass is to aim your boat at a fixed landmark or buoy, and then take the magnetic bearing of the landmark by placing your chartplotter's cursor on it. Then compare that bearing with the compass heading. As long as the landmark is more than a mile or so away, the bearing shown by the chartplotter should be the same as the compass heading, give or take a degree.

CLEAR CHANNELI'm thinking about getting a satellite radio receiver so I can download all the marine weather products that are available these days. But I'm curious: Will I have to mount one of those softball-sized antennas above my deck?

HENRY MEYER, CHICAGO, ILLINOIS

saip_0909_04_z+answers_question+gordon

GORDON WEST REPLIES:

Before you do anything about mounting the antenna, first check with your marine electronics specialist and make sure that the satellite radio weather products you plan to receive will be compatible with the charting program you have or plan to use. Navico's Northstar, for example, includes the Sirius weather module with Shakespeare's Galaxy softball-sized antenna system, and this antenna can pull signals in through fiberglass. Even so, if you have a deck with a teak overlay and it is covered with seawater, chances are good that reception of satellite signals will likely be blocked.

Related

Outremer45

Boat Review: Outremer 45

It’s funny the way things that work right almost inevitably tend to look right as well. Case in point: the Outremer 45, a catamaran that can’t help but turn heads with its large rig, nicely sculpted cabintrunk and narrow, purposeful bows. Better yet, under sail the boat more than ...read more

Sunset-Tyrrel-Bay

Charter: Glorious Grenada

In the wake of the hurricanes that devastated the Virgin Islands last year many charterers ended up going farther south to Grenada and the Grenadines where they found the sailing excellent and the vibe just fine“God must have been a sailor when he created the Caribbean,” a friend ...read more

WaterLinesNov

Waterlines: Tangled Up in Pots

I learned to sail on the Maine coast as a boy, and one of the things my elders taught me was to respect fishing gear. If you got caught up with a lobster pot, you did everything you could to get clear without cutting the pot warp. It represented a family’s livelihood and thus was ...read more

7353

Harken’s Reflex 3 top-down Furler

Furl PowerAre you afraid of flying—spinnakers, that is? Harken’s new Reflex 3 top-down furler will tame A-sails on monohulls from 44-58ft and multis from 39-55ft, and Code 0’s on 39-54ft monos and 36-50ft multis. All you do is heave on the furling line and the sail will roll up ...read more

TOTW_PromoSite

SAIL's Tip of the Week

Presented by Vetus-Maxwell.Got a tip? Send it to sailmail@sailmagazine.comDitch the stress Owners of high-freeboard yachts best boarded via the stern sugar-scoop like to back them into a slip, but the process can be fraught on a windy day or when there’s a current running, ...read more

Sun-Odyssey-490-Bertrand_DUQUENNE-aft

Boat Review: Jeanneau Sun Odyssey 490

True innovation in monohull sailboat design can be a bit elusive these days. That’s not to say that there are no more new ideas, but it does seem that many new tweaks and introductions are a bit incremental: let’s say evolutionary rather than revolutionary. Just when it seems ...read more