Wave piercing experience

Anyone has first hand experience with wave piercing boats?

 

I do. Some intentional...some not....
I think it's fair to say that Phil Hercus was the re-inventor of the modern day wave-piercing cat, of the kind that Incat used to great commercial effect and revolutionsed modern ferries in the process. I went to school and am good friends with the son of Incat's founder, so I have enjoyed a backseat ride as the wavepiercing cats were developed. There are those who, with some legitimacy, say that wave-piercers achieve little more than an equivalent narrow water-planed cat would do (the now departed Ad Hoc was one).

On the not intentional front, I once stuffed our 23 foot Formula thru the back of a wave whilst running downhill. Need less to say, it made for a far less comfortable trip than I had intended!

My most recent wave-piercer experience was hardly a world-changing event, but I helped Pete Bethune move the Ady Gill (formerly Earthrace) from one berth to another. It was quite a thrill for my 7 year old son to fire up the engines on the "bat-boat". It became somewhat more poignant when only a week or so later, they chose (rather unsuccessfully!) to play chicken with the Japanese whaling fleet....

 

How is the ride like?

 

In the right sort of conditions - what I would describe as surface chop - they are very smooth. And the big ones are deceptively fast. Get the wavelength wrong, however and they can be very uncomfortable. Many a passenger has had to resort to the chuck bag, due to the unusual motion the often presents itself - particularly in large swells.
Not unlike any vessel I guess, drive them too hard when it's really rough and they can be downright dangerous. In the early days, the afformentioned founder was nearly killed when an entire bar unit was thrown from its mounts, as a result of coming to a shuddering halt after plowing into a big wave at night.
Rocks, on the other hand, pose no real problems at all!....

 

I seem to recall that someone (Martin Renilson?) criticised this aspect of wave-piercer behaviour and it caused quite a shitstorm at Incat at the time.

I also vaguely remember that it was written up in "The Australian" newspaper at the time. Do you have a better memory of that? I'd love to see the article again.

Cheers,
Leo.

 

Sorry Leo - you're talking about the ferry, not my efforts with the Formula I assume...?
My recollection - and that's all it is - was that it was the Spirit of Victoria ( http://www.incat.com.au/domino/incat/incatweb.nsf/v-title/016/$File/0160001EH.jpg?OpenElement ) , which was the forerunner to the current shaped cats. But in thinking about it, it may have been the Tassie Devil ( http://www.incat.com.au/domino/incat/incatweb.nsf/v-title/017/$File/0170001EL.jpg?OpenElement ) , on her way across to WA for the America's Cup... so long ago....

Either way it would have been around 1985 - 1987

 

Yes, I meant ferry-size wave-piercers, and no, it was around 1995 or later.

I'll keep hunting,
Leo.

 

Fleeing for a sudden storm I had to turn the boat around between mountains of water to reach a sheltered bay. The following sea lifted the stern and threw the 17' Glastron bayflite in the wave in front of us.

A wave piercing experience followed by a submarine one. We lost the windscreen, the hood and almost everything that could float, but the 5 of us survived.

I prefer staying on top.

 

Hmm... don't remember that one....
The incident that I referred to was definitely in the 80's.... though I don't recall it getting much press

 

Leo,

Your recollections are reliable. There seem to have been several 'deck diving' incidents on larger catamarans over the years. There was certainly an article on the subject in The Australian and I may still have a copy of it... but where? Also Martin Renilson was interested in this behaviour and was probably quoted in that article. As Will has indicated I also vaguely recall hearing that 'Spirit of Victoria' encountered such an incident and this may be what prompted Incat to modify the WPC design in subsequent craft to incorporate a forward centre hull. Even so, such incidents have also occurred in later designs. Again, Will's recollection of the incident on Tassie Devil (or 2001??) on trip to WA for America's Cup is consistent with what I recall once hearing. Worth noting that the occurrence of deck diving isn't unique to WPCs, it can also occur on conventional catamarans. Even surface piercing hydrofoils, which behave quite well in head seas, can suffer from plunging in following seas. Possibly monohull fast ferries are less prone to such diving incidents than catamarans but they probably broach instead when operating at same speeds in a similar sea conditions!! Not sure which I prefer...

 

Whats the definition of wave piercing. My semi displacement cat has bulbous bows , does not climb a hump just goes faster and faster,--is that a wave piercer?

 

The only experience I have had with a wave peircing boat is a cat that goes out to the Great Barrier Reef to take tourists.

Looked the same as an ordinary cat except it has a very sharp bow. What other design modifications are required, I wouldn't have a clue.

Looking at the way the boat went into the waves, only fairly small ones, I would say it allows the boat to go faster but doesn't smooth the ride out at all. The hull peirces the wave but due to boyancy the hull still lifts and drops after it has been through the wave. When the hulls are not hitting the waves square on it creates what appears to me an very bad motion.

Instead of rolling the deck goes up and down bloody hard to walk on.

So in my opinion, worth at least 2 cents they go faster but don't give a better ride.