Kolibri SeaCat KM-380

[Fenlander]

Like our river trip the other day you have a good bit of sun. That really is a smart looking sib-cat. Despite not liking the nothing in front of you feel at sea with even the Elling she'd appreciate the walk on/off bow at the slip.

[Fenlander]

She'd as in Mrs F.

[Steve509926]

Originally Posted by Fenlander

She'd as in Mrs F.

You cut that one very, very close David! Hopefully "she" hasn't read it yet and you've got away with it.

[Fenlander]

Got to be fleet of foot both in reality and when posting.

[chipko]

Originally Posted by Fenlander

Like our river trip the other day you have a good bit of sun. That really is a smart looking sib-cat. Despite not liking the nothing in front of you feel at sea with even the Elling she'd appreciate the walk on/off bow at the slip.

Thanks, yes a cracking day on the river.
Also liking the looks but a knot or two down on the Elling at the moment, so more work to be done.
Yeah the ‘landing craft’ bows pretty cool….I’ll just have to resist heading full chat up the beach and sprinting off just like the Zapcat boys.

[chipko]

Another couple of outings on the river and a few more observations.
Motor now raised 30mm with no ventilation and much reduced splashing at speed, could probably go a tad higher but happy as is for now. One up plus kit saw 21.5 knots average with the 15hp pulling 5500rpm on an 11” prop.

Now the not such good news.
The last river trip saw some stretches of very flat near glassy water conditions which exposed a potential hull flaw. At fast cruising speeds of over 17/18 knots, occasionally and on very flat water, the air cushion could be lost and the tunnel hull sucked down to water level. This then deforms the floor, creating in effect a hooked hull. Trying to accelerate through this just exacerbates the problem, sucking the stern even lower into the water, raising the bow and lots of splashing from motor. You have to slow down and power back up onto the plane to break the cycle. Have to admit this only seems to occur randomly and on very flat water, but feel my initial concern on the reduced height (100mm) of the tunnel hull is responsible for this phenomenon.

Of course on the sea, where very rarely the water will be glassy smooth, then this issue may never manifest itself. Won’t have the opportunity to find out conclusively until Spring though when back at the coast.

So for now at least, giving the Kolibri a thumbs down from me. Shame as it’s a nice looking piece of kit which performs really well apart from this, but we tend to run mainly maxed out so can do without any untoward little idiosyncrasies lurking in the back of my mind.

For many it would still be a great choice.

[Steve509926]

Originally Posted by chipko

Another couple of outings on the river and a few more observations.
Motor now raised 30mm with no ventilation and much reduced splashing at speed, could probably go a tad higher but happy as is for now. One up plus kit saw 21.5 knots average with the 15hp pulling 5500rpm on an 11” prop.

Now the not such good news.
The last river trip saw some stretches of very flat near glassy water conditions which exposed a potential hull flaw. At fast cruising speeds of over 17/18 knots, occasionally and on very flat water, the air cushion could be lost and the tunnel hull sucked down to water level. This then deforms the floor, creating in effect a hooked hull. Trying to accelerate through this just exacerbates the problem, sucking the stern even lower into the water, raising the bow and lots of splashing from motor. You have to slow down and power back up onto the plane to break the cycle. Have to admit this only seems to occur randomly and on very flat water, but feel my initial concern on the reduced height (100mm) of the tunnel hull is responsible for this phenomenon.

Of course on the sea, where very rarely the water will be glassy smooth, then this issue may never manifest itself. Won’t have the opportunity to find out conclusively until Spring though when back at the coast.

So for now at least, giving the Kolibri a thumbs down from me. Shame as it’s a nice looking piece of kit which performs really well apart from this, but we tend to run mainly maxed out so can do without any untoward little idiosyncrasies lurking in the back of my mind.

For many it would still be a great choice.

I suppose it's fortunate that it is rare that we have flat water, mirror like conditions.
I have experienced a similar problem on Ullswater and Loch Long when Redneck has been "stuck" to the surface of the water and I've not been able to break free and get up on the plane. It feels as though you are pushing a wave of water in front of the sib. On both occasions I was looking forward to achieving maximum speed only to have my hopes dashed.

[Fenlander]

It’s a shame these cats can be problematical to get performing well across all areas. They are so efficient on modest outboards.

Re this issue I’m thinking F1 ground effect and Bernoulli’s principle of gas and liquid dynamics.

[chipko]

Originally Posted by ;Fenlander

Re this issue I’m thinking F1 ground effect and Bernoulli’s principle of gas and liquid dynamics.

Oh bugger!……..and there’s me thinking it’s just the bleedin floors been put in too low…..simples

[chipko]

Managed to get the Kolibri out for its first sea trial last week on flat seas with a brisk south easterly breeze whipping up a nasty little one foot chop.

Easy pull through the dunes fully loaded on the moon buggy trolley and an easy launch on the big orange transom wheels. Running the Yam 15 raised on 40mm packers and trim position 2 with zero ventilation and minimal splashing. Will also run trimmed out on pin 3 with some ventilation on tight turns under power. Currently breaking in the motor so limited to 4000 revs but still recorded 19 knots one up plus kit and 12l of fuel. Should be good for around 22/23 knots at full chat methinks.

Boat handled all as expected from a sibcat. Tracks well, corners flat with tenacious grip and a relatively smooth ride at speed when you can work the air cushion. Thankfully couldn’t replicate the weird handling trait experienced on the glass smooth river water. Now running tubes at 0.2 bar, very low 0.15 bar recommended, which feels much better and may even try 0.25 bar which is more the norm.

So liking it again now, and for a grand it’s a lot of boat. Yes it’s built to a budget, and some details reflect this, but lots of plus points also like fully welded seams, prv’s, big tubes, plenty of grab handles etc. Oh, and I like the colour!

[Fenlander]

Great report Chipko. Has the black Toyamahatsu been retired now?

Good to see the actual Yam seems a perfect performer for this cat. I was reminded on our outing last Thurs what an even tempered OB these Yamahas are re starting, rock steady idle and lack of splash/ventilation. Also it looks right on that cat. Much as I like the Yamaha for what it does I always thought the black Mercury 15 2T with its more squared off cowl suited our Aerotec better.

I have to say though that's one of the nicest looking cats (or sibs) with its own styling complimented by your orange accents. Looks quite special.

[chipko]

Thanks Mr F for positive comments and liking Toyamahatsu for the clone….up there with Yamahaha. No not retired hopefully as keen to monitor reliability/performance over another season, just have too many boats and motors! A back to back test with the Yam is pencilled in sometime this summer.

Agree these Yams are sweet motors for sibs/sibcats and the quality of finish seem a notch above the other big makes.

Also agree the Kolibri SeaCat looks very smart in its grey/orange livery. Can’t keep both the Elling and this though, one will have to go. Difficult choice but really like the Elling and they’re not made anymore, so reluctantly it may be the Kolibri moving on. Not before we’ve done a lot more testing and had some fun playing in the surf though.

[smallribber]

Excellent result. As you know I have tested the little Aqua Marina Aircat 335 and loved it. It would be interesting how the extra length of your one improves the ride etc

[chipko]

All things being equal a 3.8m will always ride better than a 3.3m.

Unfortunately length matters with this boating lark.

[Steve509926]

Stil loving that colour combo. Think the red of the fuel tank clashes a bit though chipko

[chipko]

A few more days out in the sibcat up here in the frozen north, and with the motor now run in an opportunity to get some brief wot runs in.

Managed a solid 21.5 knots one up plus kit pushing 5350 revs on an 11” prop. I think there’s a little more in there with a bit of fettling, more later. As a comparison our Elling has shown 23 knots, with me plus kit, and that’s on the Chinese clone pushing 5600 revs and same 11” Yam prop.

At 3.8m long the ride is great whilst pushing on in chop and mild swell. The extra length and wide bow channel enough air in to keep the bows floating above the chop and all this comes in at around 18 knots/4500 revs. Approaching max speed into wind the bows do start to feel a bit light but a bit of judicious throttle control keeps it all manageable. Don’t think we’ve been anywhere near flipping but wouldn’t want to be on the 4.2m version one up. Of course two up and/or moving kit and yourself forward will address this, so not a problem.

At max speed/wot have noticed floor still deforms slightly near transom despite running a little above pressure, and splashing increases markedly. I might cobble up a ply thrust board to fit under the rear 600mm of floor to see if this improves matters, and may even gain the knot or so lost to the Elling.

For a budget boat still lots of fun though.

[smallribber]

Looks like it goes very well indeed. Those chaps in Bury St Edmunds certainly came up trumps.

Hoping to get some more use out of my 2 cats soon

[Fenlander]

Lovely looking outfit and huge fun be it powered Yamaha or Yamahaha. Going to perfection in those images.

You are very fortunate to be able to have immediate access to the sea for long periods during the summer. I was going to use the word lucky but I'm sure it was hard work and good planning rather than luck.

So what's next I wonder......

[chipko]

Thanks and consider ourselves very fortunate being able to be so close to the sea during the season. Still surprisingly challenging to time our visits with favourable sea conditions though.

What’s next? Hmm. In no particular order;
Get the Elling, Kolibri, Yamaha and Yamahaha all on the water together and find a winner.
Test the new Boatworld Cruiser.
Get the red Aerotec inflated and on the water while it’s seams are still intact, to reaffirm it’s still ‘the best of the best’
Sell the rib, no takers yet.
Get our new hard boat out more and run in….only managed one trip so far…Doh!
Finish building my big shed and re roofing a leaking dormer on the house….now urgent!

[User name]

Originally Posted by chipko

...and Yamahaha

Still gives me a chuckle when I say that in my head.

If you ever fancy stickering it up, send me on your details/dimensions and I'll post a couple over to you.