I didn't go aboard the Dana but have spent a good part of two days at the show. The number of sailboats and powerboats at the Boats Afloat area is down, but yes, the larger sailboats are all at the Lake Union venue. I paid genuine money to hear Nigel Calder on DIY diesel maintenance. I found that I knew more than I thought I did. His 3-hr class on power generation and allocation was like drinking from a fire hose. He and the rest of his group have amassed a huge amount of data on the entire onboard power cycle from fuel consumption through various diesel/electric/battery combinations to the flywheel, transmission, shaft and prop. The fuel flow, torque, and other instrumentation allowed them to get precise figures on various factors affecting efficiency in the entire system. Calder recognized that the emerging battery technologies are game changing. The most accessible off-the-shelf batteries are the Odyssey Thin Plate Pure Lead (TPPL) cells which can accept charge like there's no tomorrow. That lets us make use of high output alternators like never before, and they have a lot of cycles in 'em making the use of inverters and combination genset/inverters much better. One of his goals is to figure out how to keep diesel engines operating in their sweet spot for best fuel efficiency, low pollution, etc. The analysis of cost per kilowatt-hr by various generation methods was sobering, especially when you factor in the amortized cost of an engine. For example, if you run the main engine just to charge batteries, then the cost is about $4/hour given a $20k engine with a life expectancy of 5,000 hours. You can quibble about the exact values, but the order of magnitude won't go away. It sounds like their research will show that a fully optimized diesel propulsion system will show that there is no way you can win with a hybrid diesel-electric system as far as efficiency goes. Calder hinted he's working on a patent to match the drive system/prop to achieve better efficiency through most of the engine's RPM range. He didn't elaborate on that.

The propeller tests gave the test Flex-o-fold prop a few percentage point edge over the competition, but only in some circumstances. I'm not sure if it was apples-to-apples because the Flex-o-fold was overpitched. (I've been touting my F-O-F prop for years!)

This may not be news to people on this BBS. I know Calder is writing about this stuff in Professional Boatbuilder, Sail, and elsewhere. It was great to see all the charts and graphs... real data, not just opinions.