I won't rehash that material other than in relation to collision at high speed which Rob raised in response to your inquiry.  Certainly the G4 is impressive but its also important to consider the extra drag of the unretractable foils at speeds below 22 knots. Perhaps lift at speeds in excess of 15 knots might reduce wetted surface and overall drag, but below this speed it will be more draggy.  I'd be interested to know some of the engineering detail.  For instance, will the foil brake before the hull fails?

In Tom Speer's Basiliscus foiling project project paper he observes: "In major collisions, such as with a semi-submerged shipping container, the craft has a good chance of escaping severe damage because the hydrofoils can be made to be sacrificial, breaking away and allowing the craft to decelerate more slowly while the hull passes over top of the object. The hydrofoils may be destroyed, but the boat has a better chance of avoiding catastrophic damage."

Its worth comparing the consequences of impact for vertical and more extreme wave piercing bows in the 20 to 25 knot range with a similar impact when foiling 10 knots quicker.  My conjecture, and Tom's, is that sacrificial or fused, pivoting foils can provide a softer landing.

https://au.groups.yahoo.com/neo/groups/harryproa/conversations/messages/10442

The only info I wan't to add that I didn't post in the Uptip section relates to this video:

Battle of the Boats

			Battle of the Boats Battle of the boats - how technology won the America's Cup: this 1 hour IPENZ lecture, hosted by Beca, was presented by two America's Cup engineers who ex...
			View on www.youtube.com	Preview by Yahoo

I've got a screenshot from the video (11:48), but this forum won't display attachments, only links.  I could send an email with the attachment but Outlook and Yahoo fail to comunicate once you start replying to messages.