Boat veers off to Starboard on its own. Ideas?

We just finished being on the hard for 3 weeks. Mainly bottom work/paint & prop service. Got splashed today and went cruising straight away. First 15 miles, everything was as usual. Then all of a sudden the bow veered to SB but I can control it back to Center. The turn to SB was more significant than a Port forward only manoeuvre. autopilot was not engaged. This happened 3 other times.. then settled down for the next 15 miles. I checked the steering hydraulic pressure.. that was fine.

Could one of the rudder be sticking intermittently from the paint? I will check steering gear but beyond that not sure where to go from here.

I would appreciate any comments or ideas.

Streff

Are you absolutely sure the autopilot is off? Maybe unhook the power to it just to make sure it isn’t activating on it’s own. Other than that if you aren’t steering when this happens then I am not sure.

My thoughts...seen all of the below:

-- Autopilot was on
-- Engine cable(s) came unclamped and throttle adjustments were inconsistent and walking back
-- you picked up something, which was generating drag on one side or binding the rudder or prop, and it broke free.

Other possibilities that come to mind
-- Rudder disconnected from ram and moved somewhat freely, giving more command to engines, current, and wind
-- Rudder ram lost pressure...." " " "

Happy hunting!

The autopilot was off at the unit but it was energized. The breaker was ON. Interesting.

Thanks for the mentioning this possibility. ?

The rudder angle is definitely worth investigating. I will dive into it first thing tomorrow. This occurred when I had the synchronizer On, which is how I usually run. Having said that, my SB throttle cable has been a lot stiffer since Caterpillar adjusted the throttle cable adjustments. Which motivates me to run synchronized more often with Port as master. I need to have that throttle cable freed up sooner than later.

Great input. Thank you

It could be engine speed changing but that would seem to be a bit more gradual. I would look hard at the autopilot first and if not then look for another cause. A friends boat would go full right rudder on autopilot sometimes. We found the cause to be the rudder position sensor. Disconnected the sensor it worked fine and apparently didn’t have to have it hooked up since he never reconnected it.

Thank you all for the comments. I disconnected the autopilot at the head and breaker off before going underway this morning. Seems ok so far. I also checked the SB throttle cable.. it was much tighter than the Port cable. I tried to free it a bit. Checked rudder connection to the ram bar. Seems ok.

I am changing my current AP, from an older Robertson to a new Simrad.. but keeping the same pump. I really liked the Robertson.. I am not sure how much we would use a chart plotter-driven AP cruising between in the PNW islands.

Streff

Glad it worked for you, it sounded like an autopilot problem. Maybe unhook the rudder position sensor and see what it does.

Just shooting wild here, but did you install any equipment in the general vicinity of the autopilot flux gate while it was on the hard? If the autopilot WAS on, and something energized on an intermittent basis near the flux gate, it could have resulted in the error you were experiencing. Please keep us advised . . .

slowgoesit said:

Just shooting wild here, but did you install any equipment in the general vicinity of the autopilot flux gate while it was on the hard? If the autopilot WAS on, and something energized on an intermittent basis near the flux gate, it could have resulted in the error you were experiencing. Please keep us advised . . .

Click to expand...

We were using the fluxgate and magnetic compasses on the recent Annapolis to Newport race. On the third day the fluxgate was off by nearly 25 degrees. A lifejacket re arm cylinder came loose and rolled over next to the sensor.

It was a nice sunny afternoon and only took a few minutes to find and fix.

Rob

slowgoesit said:

equipment in the general vicinity of the autopilot flux gate while it was on the hard? If the autopilot WAS on, and something energized on an intermittent basis near the flux gate, it could have resulted in the error you were experiencing. Please keep us advised . . .

Click to expand...

BTDT. Bose portable speaker. Unfortunately, at the time, I was near a place identified on the chart as "Magnetic Point." Complicated the trouble shooting considerably.

By any chance does the OP's 45' Californian MY have fin stabilizers?

Very interesting thoughts. Yes, the boat has fin stabilizers. I did not have anything new installed near the AP gear. The painter was sloppy when painting the rudders, paint was all over their rotating joints. I initially thought that one of the rudders got stuck.

When this occurred we were crossing the Strait of Georgia, the AP was energized but not turned ON. So in open waters, easy to manage but if it happens whilst docking.. that can be an issue.

One of the reasons I am upgrading the AP is that the Robertson terminals that connect to the back of the unit are getting wonky

Today I turned the AP off at the breaker and disconnected the terminals. We travelled 12 NM with no trouble. Will see what happens tomorrow.

Thank you

Streff

It happened to me so I know how scary and confusing that situation is.

Turned out that the boat yard, Inter bay moorings here in Tampa failed to put the key lock back in place and the clamps on the Rudders slipped and didn’t know were 20° off. To steer staring by my auto pilot had to be at 12 degrees.

It was only after messing with the auto pilot the turnbuckle all sorts of things did we decide to loosen the clamp at the top of the rudder and found that the key lock was missing.

Once we put the key lock back in, set the rudder, did it steered straight again

Shaunc said:

It happened to me so I know how scary and confusing that situation is.

Turned out that the boat yard, Inter bay moorings here in Tampa failed to put the key lock back in place and the clamps on the Rudders slipped and didn’t know were 20° off. To steer staring by my auto pilot had to be at 12 degrees.

It was only after messing with the auto pilot the turnbuckle all sorts of things did we decide to loosen the clamp at the top of the rudder and found that the key lock was missing.

Once we put the key lock back in, set the rudder, did it steered straight again

Click to expand...

I hope you had a "discussion" with the boat yard that did the work!

Thank you all for the comments and ideas. After exhaustive troubleshooting, it seems that despite the fact that the Autopilot was turned off at the helm (it’s breaker was On), the AP turned the steering on its own.. either hard to SB or Port. It never did that before and was very disconcerting when it happened. With the breaker Off and the connection to the back of the AP disconnected, we has no further issues.

this older Robertson AP was doing fine but it’s wire terminals were getting wonky (very difficult to fix). I had put in a request with Robertsonrepair to buy a set of new wires with good terminals but had not heard back from them.

It’s probably time to upgrade..It’s not going to be easy as access is difficult. Also lots of drilling will be required. The usual fun time.

Streff