A mariner can never really "trust" anything except him or her self. Charts are an aid to navigation
- they are one of the tools a skipper
uses. But they can be incorrect, outdated or incomplete. Similarly, Navigation
Aids (NavAids) - channel marks, lateral marks, safe water marks, special marks, isolated danger
marks, etc - are an "aid" to navigation but cannot be 100% relied upon. Sand bars shift, buoys can drag, coral reefs
The best tool is the master's senses and the use of back-up systems. If you navigate solely trusting your GPS
, for example, you will eventually come unstuck (or get stuck, actually LOL).
Of course, if you have extensive local knowledge - go for it. But when navigating a new waterway, especially a channel or approaching an anchorage, you should always
use caution. Of course, you should have consulted the chart (both paper and electronic), be using your GPS
, have you depth
gauge alarm set. But more importantly, you should have your senses tuned - eyes scanning ahead; looking for subtle changes in the colour of the water, the flow of the current
or tide, disruption in the water flow and wavelets (which can indicate shallow water), watching other water traffic, etc. Rely on your gut feeling. And if in doubt, approach dead slow - if you bump into something at 1 knot
you probably won't sustain damage to the vessel and can reverse off...
Interestingly, the requirement for the master of the vessel to 'Keep Proper Lookout' at all times, includes below the water surface! If you're not sure what hazards may lie submerged then you probable shouldn't be going fast! A few years ago when I was working for NSW Maritime as a Boating
Officer, a guy sent an invoice to my manager for a new outboard
because he was travelling at speed and hit a submerged rock. His take was that NSW Maritime should've had that hazard buoyed. My manager sent him back a fine for 'Negligent Navigation' for failing to Keep Proper Lookout and not travelling at a 'Safe Speed'... true story.
chala, in 2004 I was motoring my 43 footer through a narrow passage
between islands in the BVI's just before sunset on approach to an anchorage. I had the paper chart out, I had my laptop
and interfaced GPS open and I was travelling at about 5 knots. Up ahead my eyes took in a few conflicting signs on the water, I slowed the boat right down and consulted the C-Map
and cross referenced it with the paper chart. They were giving conflicting info (regarding exact reef position) but both were saying the passage
was clear ahead, deep water. But I didn't like it, my senses were telling me different and my gut was too. I stopped the boat and slowly circled back, then placed a crew member
on the pulpit to scan ahead. I then proceeded very slowly, liasing with the crew member
, at times stopping the boat to run forward to the bow and double check myself.... long story short, we navigated through safely and got to our anchorage and soon had the Mt Gay rum
. But there was a finger of reef jutting out across that passage when both charts said there wasn't! If I had solely trusted the chart(s), we would've hit reef....
I know it's a long answer to your question but No, don't just trust the chart. Use all the tools at your disposal but in the end you are the Skipper
and you are responsible for safe navigation.