Ship rides on air ...

[willmarsh3]

... to save fuel

http://www.sciam.com/article.cfm?id=air-cavity-system

hope this works out ok.

[ahp]

I remember reading some place that some small Scottish lapstreak boats would, when conditions were ideal, "come loose". They would sail much faster and make a noise like they were being dragged over gravel. Perhaps the laps were trapping air bubbles. Is this the same thing?

[Jay Greer]

I remember reading some place that some small Scottish lapstreak boats would, when conditions were ideal, "come loose". They would sail much faster and make a noise like they were being dragged over gravel. Perhaps the laps were trapping air bubbles. Is this the same thing?

I believe so. It has been my own pet theory, for many years, that the West Coast practice of groovng topside seams helps to create more of a laminar flow as the boat heels on to it's sailing lines since the grooves trap air as the bows lift and settle on a reach. I have found this to be true of the Common Sense Sloops that are faster than other boats in their class. The difference being that some have their hulls grooved.
In addition, Folk Boats that are lap streak planked are said to be a bit faster than the ones that are carvel planked.
Jay

[Windsong]

30 years ago my grandfather suggested a "bubblecarpet" under a ship would reduce drag and decrease fuel cost. Oh well.
Happy New Year!
Lars

[coelacanth2]

WB article a few years ago on a very old lapstrake sailboat, Swedish or Danish built, (Edna Fransden? perhaps) mentioned just that possibility. The boat's owner noted that she trailed a hugely bubbly, phosphorescent wake behind her, and was often faster than some much newer, racier boats. Glued ply lap DEVA or ARAMINTA for the Newport to Bermuda, anyone?

[willmarsh3]

Kind'a anecdotal but this might help explain why my shellback dinghy glided ever so gracefully over the water while being towed behind my boat while under sail no matter how fast she was going. She would surge forward after the tow rope came under tension and stretched a bit. The tow rope became slack very quickly but she would coast forward for a while before gradually starting to fall back and repeat the cycle. The shellback dinghy is lapstrake as some of you know.