My First Dirty Bottom Experience

No, not that kind of experience. Get your minds out of the gutter

We are doing a two week trip on our boat in Baja. Arrived here and could see the bottom wasn’t cleaned. Our divers had some equipment issues and got behind schedule for several weeks. We went out for a day trip and all was running great. However, after coming up to around 1800+ rpm’s I glanced down and saw my engine load was showing 93% on both sides - WTF? I should be around 65% or so at that rpm. It did come down some after the initial speed up but still way high. In a bit of a panic I’m looking at everything to find the problem. All gauges were green, no other obvious issues, no heavy smoke, etc. I was racking my brain trying to figure out what could cause this on both engines at exact same time? Then it dawned on me, could the bottom be that dirty? After about 15 mins of run time it did drop to 77% load at 1825 rpm. Better but still way high. We were only going a short distance so I just slowed down and we finished our day trip without incident.

Divers showed up yesterday morning before our departure. They said the bottom wasn’t terrible (because we just ran it) but the props had a lot of those rock hard white worm thingys on them. They did a good job getting her all cleaned up. Left the marina yesterday and all back to normal. 1825 rpm and load at 64% with throttle position 63%.

I’m aware of how a dirty bottom can affect things but I was not aware of how significant even mild fouling can be an issue. Time to get prop speed on my props and shafts at next haul out.

Here’s my morning view somewhere in Baja.

Thanks, good info. I have the bottom cleaned monthly but they were almost 3 weeks late this time. I’ll monitor to see if monthly is enough. I might have to increase interval in the summer months. Especially given we use it less often this time of year due to the heat.

Good info, thank you! Funny you mention leaky current from other boats. I just moved slips as I’m convinced the boat that was next to me was eating my transom zinc plates. I’m already on #4 and I’ve only been here 7 months.

This is a pretty high end marina. Lots of security, cameras, etc. Most boats here are bigger, newer and way more expensive than mine. I’m convinced they only let me in to lower the net worth of the neighborhood a bit . This also lets the big boys feel better about themselves when they see my old boat here. There is no way I’m going to go and open anyone’s breaker. The potential damage or even loss of their freezer food is probably worth more than my house.

Sounds like someone was a little grouchy yesterday evening

I guess things are different in Florida. I’ve never been in a marina anywhere on the left coast (high end or otherwise) that I have seen them go around probing the water testing boats for stray current. I’m not saying it doesn’t happen, just that I’ve never seen it. The boat I suspected is actually a very nice Hatteras Sportfish. But some of the maintenance and upkeep looked a little lacking. If I continue to eat zincs at the new slip I will be probing my own boat and the docks and boats near me.

Yes but that was before I renewed all the wiring throughout the boat for all bonding. Haven’t issues like this since then.