A Second Look at Dive Boat Engine Exhaust

We often get letters that you should also read. Here’s one from reader Dave Marchese (Hummelstown, PA) about our June article on the Baani Adventure’s faulty air compressor, which killed one diver and injured 10 others because of carbon monoxide poisoning.

Dear Ben,

My wife and I were on the Baani Adventure in November 2007. In addition to the ship being in a general state of disrepair, the food being poor, and the bedrooms containing cockroaches, there was one dive that seriously scared me and now, after reading your article, scares me even more.

After that mid-trip dive, at least half of the 18 divers were significantly dizzy, had severe headaches, and just “didn’t feel right.” I have done 800 dives, and most others were similarly experienced, so we all knew this was a new sensation. We discussed it and were convinced it was bad air. Very foolishly, none of us made a stink over it. Instead, I examined the compressor. It was a very new-looking Honda unit, and the donhi exhaust seemed to be a good distance from the air intake. I didn’t really know what I was looking for but it didn’t seem to have any obvious issues, so I decided to forget about it. I’m ashamed in retrospect, but I guess we all wanted to believe the best while we were on vacation.

I planned on writing a Chapbook report but when I returned home, the new Chapbook was in my mailbox, full of scathing articles about the operation. I figured the word was out and they were finished, at least to Undercurrent subscribers. However, now I really wish I had written because it could have saved a life. I didn’t feel right accusing them of such a serious offense when I had no concrete proof and I didn’t see any obvious causes during my simple, scratchmy- head compressor inspection. I’ll never make that mistake again. And I’m going to buy a carbon monoxide detector.

****

Dear Dave,

Buying that detector is a good idea. Marine engines produce more carbon monoxide than cars because they don’t have any after-treatment of the exhaust. It was only a few years ago when the U.S. Environmental Protection Agency listed CO as a deadly hazard on houseboats, especially when people swam or floated near the stern swim platform when the generator was running. Deaths formerly attributed to drowning were in fact carbon monoxide poisonings of people swimming into an air cavity. Boaters were also being overcome in “fresh air” poisonings while sitting on stern decks and swim platforms.

While cars have had catalytic converters for decades to reduce tailpipe emissions, the EPA has begun setting standards for marine engine emissions just in the last decade, and the job is only half-finished. Outboard engines are now manufactured under new EPA standards, phased in through 2006, and the next set of regulations will cover gasoline sterndrive and inboard engines. But that’s just the U.S. As we saw in the Baani Adventurer incident in the Maldives, some countries where dive trips take place have no regulatory body for boat and diving safety.

There’s no magic potion yet for reducing CO emissions. Ethanol is making a push in the boating industry but has so far proved problematic in boat engines because it can dissolve fiberglass fuel tanks and it attracts water. Alternative power sources like hydrogen and hybrid engines are just starting to be tinkered with.