Saturday, April 30, 2011

Electronics meltdown at sea...

We departed Charleston before 7 am on Monday headed offshore, directly to Beaufort, NC.  The 205 nm offshore route would take us all day and all night. We'd arrive in Beaufort/Morehead City around 10 am on Tuesday morning.

We've gone offshore here quite a few times. Going straight offshore saves a lot of day trips by skipping the two large scallops of the coast in South Carolina and North Carolina. The only hazard is a very long, 15 mile shoal that extends from our beloved Bald Head Island out to sea. It is too shallow to go through although there is one small "slue" passage about 12 miles out. Taking that shaves a few miles from the trip and maybe saves an hour.

The slue is marked with a few non-lit buoys but they show up on radar miles ahead. Our path would have us reaching the slue at around 11:00 pm in pitch darkness since the moon wasn't supposed to rise until 2:15 am.

The seas were a bit rougher than we prefer but definitely within our comfort range. Everything was going well as we approached the slue. Our darkened pilothouse was filled with electronics providing position on multiple screens, radar overlay, autopilot, depth, wind, rudder, sea floor image, a second depth sensor - all designed to keep us in the right position.

Just as we were approaching the first mark on our route for the slue, all screens showing our position went dark. Our main chartplotter just blinked and turned off. It controls the main GPS on the arch so it went down too - nothing would bring it back. The autopilot gave up and went offline forcing us to manually steer. The phone next to the helm running the exact same route showed a red GPS location meaning there was no GPS signal being received (I wrote that software). We had no radar display in the pilothouse with 4' waves coming from the south on our starboard side and no way to "see" our position nor the position of the upcoming buoys.

Even though we're in our 9th year of doing this long range type of cruising, it was unsettling but we were quite calm about it. Within 30 seconds, a backup GPS was flipped on. We now had full position display using the same route we were following but on a 2" phone screen.  In 2005, as an experiment, we traveled from Maine to Key West only using that 2" screen so this wasn't uncomfortable at all.

iPhone's and iPads were all turned on monitoring our exact position on the charts. In another 4 minutes, Karen's laptop was booted and we were running Coastal Explorer using a second backup GPS. The autopilot was now operational as we had it following our planned route. Karen had just been testing Coastal Explorer's latest version so we knew it was current with the latest charts loaded. We could have easily selected one of 5 other software products to use.

The issue was radar. We have a backup screen but it's on the flybridge. The radar was on and displaying an image, but we'd now either have to stay all night up there, or walk up and down to take a radar view every 10 minutes. We have some strict rules about going outside when the other is sleeping so we decided that the person off-watch had to sleep in the pilothouse and a 10 minute timer would alert us to make a radar view, up and back to the flybridge.  Looking out 6 - 24 nm on radar, 10 minutes would be enough time to have any non-ship come into view. Any ship would be visible by lights for many miles ahead.

We moved along like this until daybreak when radar became less important given the clear day. We arrived at the Beaufort inlet at 9:00 am, Morehead City by 10:00 am, and continued on to the Neuse River about 40 miles further along the ICW finally dropping our anchor in the South River.

The next morning, the chartplotter and all onboard electronics worked perfectly and have been continuously on since.

This is all a pretty good example of why backups are needed. We have more than 5 backup GPS's. We have a backup way to view radar although it adds an obnoxious procedure. We still have no idea what happened to the main chartplotter but we also know we're ready if it goes kerfluey again.


John said...

I'm not telling my wife about that one!

Jens said...

Thank you very much for that great post. It shows how good seamanship should be performed.

Assuming you allow it I will back link to that article from my website.

Again, thanks and always enough water under the keel.