Letters from You - October 2019

Hi Pat,

Not sure you remember us, but you helped us move our Meridian 391 from Alameda to Village West in June 2017. If you are looking for subjects to write about, we had an experience with our CO monitor that we didn’t know existed and you may want to share with other boaters. 

We had our CO monitors go off and thought we had CO built up. (Our boat is diesel). I discovered that is was not CO. After a lot of research on the web, it turns out that CO monitors also detect hydrogen gas (a by-product of charging batteries as you know) which is as deadly as CO but is also extremely combustible! So, if the fumes don’t kill you, the explosion and fire will.

We had a battery charger that failed to stop charging and the hydrogen gas tripped the CO monitor. Something that I never knew or even thought of. If you have questions or comments, please feel free to contact me.



Yes, I do remember you and the boat and thank you for writing. I was not aware the CO detectors would also alarm with hydrogen gas. Looking up the subject it seems that hydrogen is part of the sensors reaction to gas and the sensors will give an alarm with hydrogen gas present. Apparently, there are CO sensors available that do not have the cross sensitivity to gases other than CO, but they are more expensive. I found industrial sensors that are marketed specifically as “dual purpose” sensors used for the simultaneous detection of both CO and Hydrogen Sulfide (H2S) and they charge a premium for these dual-purpose sensors. Good marketing to sell a flaw as a feature.

Not giving the subject a whole lot of thought however I am inclined to think that our marine CO sensors being sensitive to gassing batteries is a good thing as long as we are aware that the alarm may not be sounding due to a high concentration of CO, but rather batteries that are being overcharged and producing Hydrogen and Hydrogen Sulfide gas. I did an article for the August 2015 Bay & Delta Yachtsman on CO detectors but did not find this hydrogen gas issue in my research. Looks like it might be time to consider an update as I’m sure that CO sensor technology has advanced in the past 4 years.

Thank you for being a loyal reader of the Bay & Delta Yachtsman.


Hi Pat,

I just read your article on the Potomac in Yachtsman magazine. You did a lot of research to describe the previous Presidential Yachts. I had been bumping into Ty Mellott at various places around the Bay, at the boat show, Walnut Grove Marina, etc. I told him to tell you hello; and, he said you were working on an article about the Potomac. The article turned out quite well.

Some thoughts on the article. I’m surprised that you did not mention Wally Abernathy who was the Port Executive Director that bought the Potomac. There is quite a story behind that day and that purchase. Wally sent six engineers including myself, over to see the Potomac when it was about to be sold. The Potomac was barely floating. Water was two feet deep over the rear stateroom decks. The water line was up to the bottom of the port holes along the side of the ship. Everything that had been up, insulation, wall board, wiring etc., had fallen after several weeks under water. There were eight, three-inch pumps running full bore trying to keep the vessel from sinking again. Imagine a 165-foot trash dumpster half filled with water and oh the smell of rotting newspapers, mattresses, mud and other debris. The group talked with Wally and we gave our collective opinion that the vessel was not worth salvaging.

The U.S. Customs Department oversaw the sale. The auctioneer first asked for a bid of $50,000, there were no bids. The auctioneer then asked for a bid of $25,000, again there were no bids. The auctioneer then went and spoke to Wally. He asked Wally if he could make an opening bid. Wally told him that his maximum signing authority for the Port was $15,000. The auctioneer then asked for a bid of $15,000. I was standing next to Wally when he raised his hand to make that bid. I still think to this day that Wally did not have the intention of buying the Potomac, but since no other bids followed the auctioneer said, “SOLD to the Port of Oakland.” Wally took a lot of heat for this purchase. The newspapers called it Wally’s Folly on April 3, 1981, 38 years ago. Have I really been there that long? Note that the initial price of the Potomac was $15,000 but the cost of the dry dock the next couple of days was in excess of $30,000. The dry dock was necessary to patch most of the major leaks. Then the Potomac was turned over to the Port Maintenance crews to clean out the ship and patch the remaining leaks. My crews did most of the cleaning and hull patching while the Utilities Group installed new electric bilge pumps and bilge alarms.

One person you may want to contact about the Potomac is Bill Morrison who is Harbor Maintenance Manager for the Port. Bill came by the ship a couple of years ago to describe how the Potomac was raised after it sank. Bill was one of the Naval Reserve divers that raised the Potomac. The story about the hull being punctured by a piling was a cover story to cover up the fact that a reservist who was supposed to maintain the pumps on the Potomac was being drummed out of the service and conveniently neglected to keep the pumps running. The Naval Reserve dive team took on the task to raise the Potomac as a training exercise. They used two 100-ton cranes. One crane had a cable through the hawse pipes. The other crane held a belly band under the center of the ship. The divers had to dig 17-feet into the mud to pass the cable under the ship. On the back of the ship the divers installed 100 tons of lift bags. Bill can tell the story better than I can. I suspect that members of this dive team managed to acquire the ship’s wheel and the ship’s order telegraph. They were on board when the ship went down but were not present when it was sold.

There is also a long story about the dedication of the FDR Pier. The pier rotted away and was torn down several years ago. I had to arrange for James Roosevelt to catch a fish at the dedication.

I’m also rather surprised that you did not mention Captain Adam Leach, Captain Skip’s protégé. Since Skip passed away the Potomac has been Adam’s baby. He was the driving force through two dry docks. Unfortunately, it seems that the Potomac has lost Adam because of family commitments. I too have had to resign from crew duties. I pulled my back handling lines a couple of years ago. The back injury was so severe that I could not walk from my garage into my house. Recovery took several weeks to be back to some level of normal, but I still get intense back pains on occasion and do not want to be a liability as a crew member.

Keep up the good work. I’m always reading your Lessons Learned articles.

Best Wishes,

John Kaehms

First Mate, Retired

USS Potomac


Great hearing from you. It has been a long time and my Potomac years were very enjoyable. Thank you for the additional information regarding the original purchase of the Potomac. I do remember the day that you convinced Wally to visit with the crew and share some of his stories. He must have been a good guy to work for and it was certainly fortunate that the auction worked out the way it did. There is so much history there and I just could not fit it all into a short magazine piece with limited space. Not mentioning Captain Adam’s significant time commitment after taking over for Skip was an oversight, my mistake.


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