Cat hull sibs are great!!!

[Easyrider]

Just thought that i would share my new experience, as it may be of use to those of you considering getting somthing that is more comfortable/faster but still easily managable.
I just purchsased myself a Ceasar surfcat ( http://www.leisureshopdirect.com/mar...boat_only.aspx )after selling my Bombard aerotec 380(im a great fan of sibs) as i wanted somthing that would have a bit more power to tow bigger toys(the 30 on the bombard was ok but i needed more ) I did a bit of digging around and tried out a couple of thundercats/zapcats but decided that i wanted somthing a bit more family friendly with a bit more freeboard so the kids would feel safer + needed more floorspace-the surfcat met all of my needs so i got one and put a 50 Tohatsu on the back, fitted mounting bolts for my old bombard launch wheels and off i went.
The thing that has really blown me away is just how comfortable it is(i have helm'd quite a few different ribs/sibs/solid crafts over the years), Im sure that most of you know , once it starts blowing force 3/4 it gets quite uncomfortable on a sib, well - it doesnt on a surfcat!!! we were quite happily cruising along at about 30 knots head to sea and not getting knocked around at all , going the other way with the sea we were doing 40+ knots and it was still pretty comfortable. The hijackers(cat hull) just slice through any chop and soak up any slamming even better than an equivalent size rib.
It would still perform great with a 30 on the back.

I just cant understand why these boats arent more popular- because im absolutely sure they would be as word gets about.

[Channel Ribs]

Originally Posted by Easyrider

I just cant understand why these boats arent more popular- because im absolutely sure they would be as word gets about.

I really like the idea of a SIBcat, great as a safety boat and obviously very exciting for blowing away cobwebs.

The big turn off for me is the price

3k takes a lot of justification, when I can have a very capable boat + engine for less and still have change to buy the wife a case of sherry.

[BumbleAbout]

I would have really liked to have seen some side by side magazine reviews/ comparisons of Gemini/ Zodiac Futura/Ceasar Surfcat and a couple of 4.5m RIBs.

[prairie tuber]

Another convert. The round nosed cat hull SIBs tend to be much more functional than zapcats/thundercats for the reasons Easyrider had mentioned.

I would imagine that the Ceasar Surfcat would perform similarly to a PVC Gemini Surf GRX 420 (the gemini's are also available in hypalon). The PVC cat hulled SIBs should give somewhat higher performance since they are lighter and can be inflated to higher pressures than hypalon (therefore a little more rigid), but the hypalon cat SIBs perform extremely well just the same.


There really aren't very many roundnosed cat-hulled SIBS on the market. The only ones I'm aware of are;

Ceasar Surfcat (4.1m - PVC only)

AMI Advanced Cat (3.0m, 3.3m, 3.9m & - 4.6m - PVC only)

Gemini Surf (3.8m & 4.2m - PVC or hypalon)

Gemini Dive (4.7m & 5.3m - PVC or hypalon)

The AMI boats tend to be a little less costy than the ones from Ceasar and Gemini, but it is definitely worth your while to inspect them in person to see how they are built and if the extra cost of a higher end brand is worth it. That is not a nock against AMI, they are better built that most SIBs out there, but the South African brands have alot more experience in the design and build of these boats.

[ian parkes]

I fancied one of those last year and went to the dealer but they weren't much help and didn't have a boat i could even look at , the open transom was also a concern for me but i could have overcome that i think .
Your report is all i had hoped the boat could be and faster than i would have expected . Would be nice to know how they perform with a smaller motor.

I ended up with a Mk3 futura which didn't meet expectations at all for me and was no better than a normal sib in a chop

[dverstege]

How fast is your Gemini P/T. I have checked them out and although strong I was surprised at the weight with motor. That said I am saving up for one next year with a 30hp 4 stroke probably the 470. I wonder how they would be pulling a wake board or tube?

[prairie tuber]

Originally Posted by dverstege

How fast is your Gemini P/T. I have checked them out and although strong I was surprised at the weight with motor. That said I am saving up for one next year with a 30hp 4 stroke probably the 470. I wonder how they would be pulling a wake board or tube?

I just checked that with a borrowed GPS unit on the river the other day.

My boat weighs about 350 lbs, the motor about 170 so the combined weight is 52O lbs. I carry about 50 lbs of basic gear in the bow locker (anchor etc..) including the weight of the locker itself. At the time, I had 2 full jerry cans of fuel (about 100 lbs), myself (200 lbs) and a buddy (250 lbs) in the boat. With the total weight of the boat, gear and people was well over 1100 lbs and I was able to do about 42 km/h with a banged up prop with a 40 hp engine that needs some carb work and the engine height still in need of tweaking.

My main concern when speccing my boat were longevity and the ability to handle large loads (eg. a dressed moose and 2 weeks worth of hunting gear), which is why I went with the heavy hypalon and the 3/4" thick floorboards. If I were to have ordered my boat now, I would have gone for the Dive 530 - not that I've yet experienced space limitations with the 4.7m, but simply because the 530 is .6m longer.

I'm guessing that a 4.1 - 4.2m PVC Ceasar surfcat or Gemini Surf would not weigh much more than 200 lbs. With a 50 hp Tohatsu 2 stroke (150 lbs) and a minimal load, I could easily see it being more than twice as fast as what my boat was doing the other day.

I should be acquiring my own GPS unit in the next few days. I'll check to see how fast the boat is with a minimal load. I'll also check once I get my carb and engine setup tweaked. My boat is rated for up to 80hp which would be pretty wild.

[Andy JC]

Originally Posted by prairie tuber

a dressed moose

Is this the sort of thing you had in mind?

[dverstege]

It’s been ten years ago that I brought down a moose. I still miss the hunt, I’ve got 8 moose and 1 caribou to my record and a lot of good eating. It’s good to know that your sib can hold up to heavy loads and still move that fast. Don’t forget to let us know your max speed when you get things in tip-top shape.

[prairie tuber]

Originally Posted by Andy JC

Is this the sort of thing you had in mind?

Is he carrying a dead bunny? That's so cruel!

[prairie tuber]

Originally Posted by dverstege

It’s been ten years ago that I brought down a moose. I still miss the hunt, I’ve got 8 moose and 1 caribou to my record and a lot of good eating. It’s good to know that your sib can hold up to heavy loads and still move that fast. Don’t forget to let us know your max speed when you get things in tip-top shape.

Wow, you've done very well. It sounds like you are originally from somewhere other than the GTA. Caribou is my favorite type of venision, but I've only had some on a few occasions.

Easyrider, sorry about the hijack (then again the thread is about boats with hijackers ). Can you post some pictures of your surfcat?

[dverstege]

Great place to live and hunt if you can find a job that pays the bills.

[Easyrider]

I havnt got any pictures yet, i'll post some up when i get around to it.
I took it out by myself the other day, and she REALLY flies and was suprisingly stable with just one person in it- i would guess i was reaching 45/50 knots, but i wouldnt want to be doing this speed into a headwind by myself though.
It also pulls a 3 man ringo with ease which was a nice suprise considering that im using a semi cleaver prop.
The power to weight ratio is brilliant- i think it works out to be somwhere in the region of 350hp per tonne!!!!
Only used about 20L of fuel in about 6 hours of boating as i wasnt going full speed everywhere because theres really no need too as shes still really quick without thrashing her

[SnappingTurtle]

A couple of questions from a new guy.

1. What is the difference between a Ceasar Surfcat, and a Zodiac or Avon with speed tubes mounted?

I just looked at a older Avon w/Speed Tubes mounted and I can't see a great difference.

2. Is it possible to add speed tubes to any Hypalon boat?

[Easyrider]

Originally Posted by SnappingTurtle

A couple of questions from a new guy.

1. What is the difference between a Ceasar Surfcat, and a Zodiac or Avon with speed tubes mounted?

I just looked at a older Avon w/Speed Tubes mounted and I can't see a great difference.

2. Is it possible to add speed tubes to any Hypalon boat?

The difference is that the sibs with speed tubes still have a centeral keel/hull-this is the part that causes the slamming in a chop.The Surfcat hull is a catermaran hull with a deep but thin sponson/hijacker either side of a flat deck-the best way to see the profile is to google an image search for "thundercat boat" or "zapcat" as these have exactly the same setup(slightly different profile though).
I should imagine that it is possible to add speed tubes, which will make it more stable at speed, but you will still get the pounding when out in a slight chop due the hull profile.
Hope this makes sence.

[Easyrider]

Forgot to add that the cat hull compresses the air beneath it which helps further with the ride characteristics.

[SnappingTurtle]

Originally Posted by Easyrider

The difference is that the sibs with speed tubes still have a centeral keel/hull-this is the part that causes the slamming in a chop.The Surfcat hull is a catermaran hull with a deep but thin sponson/hijacker either side of a flat deck-the best way to see the profile is to google an image search for "thundercat boat" or "zapcat" as these have exactly the same setup(slightly different profile though).
I should imagine that it is possible to add speed tubes, which will make it more stable at speed, but you will still get the pounding when out in a slight chop due the hull profile.
Hope this makes sence.

I have been looking at the Cats for a couple of years now, but have yet to see one in person other than one I saw go past on the Main river at about 45/50MPH one day, by the time I got in the boat, he was long gone. A friend who spoke with him later told me he was a South African, here on vacation, and I never saw it again. I think I would enjoy one, but they are pricey.

I saw the Avon with the Speed Tubes last week, and to tell you the truth I really didn't consider the influence of the inflatable keel. I would think it would have a affect on the tunnel effect by reducing the lift.

Would Speed Tubes mounted on a flat bottom SIB with a aluminum, air floor, or wood floor, without the inflatable keel, achieve the same overall lifting affects as a “Ceasar surfcat”?

[dverstege]

Just a guess but speed tubes like the Zodiac are very small according to the pics, but the Gemini’s and the true Cats actually have large pontoons that keep most of the hull “floor” out of the water. I would say that the Gemini and zap-cats would be a lot faster but what would the advantages be in Zodiacs eyes to do it there way?

[prairie tuber]

Originally Posted by Easyrider

The difference is that the sibs with speed tubes still have a centeral keel/hull-this is the part that causes the slamming in a chop.The Surfcat hull is a catermaran hull with a deep but thin sponson/hijacker either side of a flat deck-the best way to see the profile is to google an image search for "thundercat boat" or "zapcat" as these have exactly the same setup(slightly different profile though).
I should imagine that it is possible to add speed tubes, which will make it more stable at speed, but you will still get the pounding when out in a slight chop due the hull profile.
Hope this makes sence.




Forgot to add that the cat hull compresses the air beneath it which helps further with the ride characteristics.

That is an excellent explanation.

[prairie tuber]

Originally Posted by dverstege

Just a guess but speed tubes like the Zodiac are very small according to the pics, but the Gemini’s and the true Cats actually have large pontoons that keep most of the hull “floor” out of the water. I would say that the Gemini and zap-cats would be a lot faster but what would the advantages be in Zodiacs eyes to do it there way?

The futura design might get a boat onto plane a bit sooner since the center keel raises the height of the boat in the water while at rest. Regardless, the cat hulls get onto plane so easily that they won't have any real world disadvantage because of this. By the way Dan, NL is the only Canadian province I haven't been to yet, hopefully one day I'll have the opportunity to tour it.

I went out today and went through about 60 liters of fuel over a 177 km round trip. The first 60 km or so was going into some very choppy waves - no other boats were out in the water (from a quite busy harbour) at that time. There is a write up titled "SIB Daytrip" in the Rib Gallery section. Link here:

http://www.rib.net/forum/showthread.php?t=25731