On Tue, 23 Nov 2004 21:46:53 -0500, DSK wrote:

Short Wave Sportfishing wrote:
This morning, while burning some old gas in the Ranger.....
2.5K - the shape of the wake is fully formed, but we're not quite
there yet.

http://www.home.earthlink.net/~tomf1...tfivestern.JPG

Actually, at this point, you're planing. The crest of the boat's stern
wave is noticably past the transom, and therefor by definition you're
exceeding hull speed... therefor planing. Of course, it's not an
either/or thing in the real world. The boat's weight is still largely
supported by displacement rather than dynamic lift, hence the hole in
the water which the wake is closing up.

Good point.

3K - this is the transitional stage where the boat comes fully up on
the planing surface. It doesn't happen in short bursts on this boat -
it literally goes from 3K to 4K all at once and your on plane. The
planing wake shape is now fully formed.

http://www.home.earthlink.net/~tomf123/threeKstern.JPG

Notice the lack of bow wave.

http://www.home.earthlink.net/~tomf123/threekbowave.JPG

The bow wave is there, it's just behind you

Yeah - I wondered how to phrase that. Thinking about it, I should
have said the bow wave moved aft.

I commend you for taking the time & effort to put some observation on
the wake. Far too many people pretend it's not there.

This boat has always interested me in that, as I've mentioned about a
zillion times, it has no bow lift and it's theoretical top speed is
about fifteen mph above what it actually gets (40 vs 55). It doesn't
act like it's supposed to. :)

Somewhere floating around I have some pictures taken astern from the
Johnson 18 when it's planing, when close-hauled and under spinnaker.
When "fully planing" there's no wave train at all, just a flat swath of
white water. Of course the hull shape is much more efficient....

I'd like to see those. I'm not sure I could agree about efficiency -
the Ranger hull is pretty efficient if only because of it's odd
performance.

TTFN,

Tom

"Bodies are for hookers and fat people."
Bender - "Futurama"