Aqua Marina - Budget Tunnel Hull SIB

[chipko]

Thought I’d start a thread on our new super cheap Aqua Marina U-Deluxe 2.98 tunnel hull sib ordered on a whim during another discussion on cat style inflatables. Ordered at the weekend, from their fleaBay outlet, boat landed yesterday.

Even though a tad busy at the mo replacing water main, new drainage runs and installing channel drains prior to relaying new drive, but hey ho went ‘awol’ for an hour or so to unpack/inflate....gotta get one’s priorities in order.

Following time honoured tradition, first inflate to be indoors, and in this case a spare bedroom.

First impressions looking good. Seems to be all as described on the tin, a no frills super light cat style tunnel hull and decent looking to boot. Obviously built to a price point it’s pretty basic with average quality finish and by no means overbuilt but we tend not to abuse our kit so this shouldn’t be an issue.

Good points, thermo welded main toob seams, cat style tunnel hull, overall looks, extremely light and flat hp air deck floor, Cat C rated and 15hp max.

Not so good, although by no means bad at all, lacking any tie down points or bow side towing d-rings, average dia. 41cm toobs, slim section rubbing strake and no under tube protection or fins, 15” deep transom (too deep, its a cat), single seat too far astern and two pre-drilled but unsealed towing? holes in transom.

No idea as yet how it will perform on the water, initially with our spare 3.5hp motor, and if a keeper will source a 26kg ‘holy grail’ Tohatsu 9.8 which should make it fly. Despite the rating reckon a 15hp four stroke would be too heavy and overkill.

For under £600 delivered, hoping this super light (28kg) Chinese pvc and air mini cat will be just the ticket to replace our trusty little Bic Sportyak...only time will tell...and no big deal if it doesn’t. Hopefully get it wet late April after lockdown and follow up with an on water review.

PS: Inflated to just over half working pressure in pics so might spot the odd wrinkle!

.

[Fenlander]

I reckon that will be huge fun as a "no trouble to lift across the beach" muck about SIB. I'm amazed they put a 15hp rating on it. Another decent motor would be the Yamaha 8hp 2-stroke which is the same weight give or take 1kg as the Tohatsu and really nicely made.

[smallribber]

I must admit that looks very nice and a lot of fun. I think my 9.8 Tohatsu would be good on that.

I am tempted to add to my fleet.

[chipko]

Hey Fenlander and smallRibbber, thanks for positive comments. Agree, 15hp four stroke suicide, 9.8 two stroke...Nirvana.

Re 15” transom depth, gut feel this will be a tad too high for the larger motors at planing speed. Underside of tubes (effectively the planing pads) are 100mm lower than transom and motor AV plate 50mm below transom. Reckon it’ll be lucky not to ventilate at that, although a cupped prop may help...common solution on these mini cats. Also if boat proves to be a keeper, not averse to cutting down transom. :whistle


If any Elling, TrueKit or Takacat guys are out there, would appreciate dropping a tape on the actual transom depth. Thanks in anticipation guys.

Couple of pics with our tiny Mariner 3.5 just to get a feel of the problem.

[Old seahorse]

Hi Chipko, I have a takacat Lx300. Boat is currently deflated, but when I get a chance will inflate and check transom height. It’s a different structure, as transom consists of two parallel tubes which have two plywood plates clamped between. I think my motor( Suzuki 6hp) sits a bit low,but will check. If yours has a good clearance between water and floor, you may find a fin is helpful in reducing ventilation, which is an issue with some cats. I had a permatrim fitted, which considerable improved this, resulting in much less wake, and improved performance.

[chipko]

Thanks Old seahorse, nice rig you have there and a quick dim. would be great when you next have boat inflated.

Good to hear the Hydrofoil improved your rig. Interesting that both Takacat and TrueKit recommend them and notice some motors in their promo videos are sporting Permatrim Hydrofoils.

Am hoping after sorting motor height all we’ll need is a cupped prop! Ever the optimist.

[Fenlander]

This is outside my experience so someone please explain why an outboard running in fairly clean water not just disturbed by a hull suffers ventilation?

[Pikey Dave]

Originally Posted by Fenlander

This is outside my experience so someone please explain why an outboard running in fairly clean water not just disturbed by a hull suffers ventilation?

I’m guessing (and that’s all it is) that the catamaran configuration raises the engine, also that air gets trapped & funnelled under the hull creating lift.

[chipko]

Having just purchased but not yet got wet, the small cheap cat style tunnel hull inflatable I fear I’m soon about to find out.

I imagine the problem lies with not getting clean/flattish water immediately over/before the prop. On a conventional hull the keel line smooths out the water as it exits the transom, but on a planing cat, the transom and hull are elevated and the water level over the prop potentially not as constant. Finding the ideal motor height will be a bit of a black art methinks.

On the Elling, my understanding of the central keel is its there to flatten out said water (small chop/wavelets) in the path of the prop.

Edit: Wot PD said above!

[Fenlander]

Ahh OK makes sense I guess that a normal hull feeds the prop a constant height of "ironed" water to a great extent yet the cat style allows a varying height between the hulls. Wonder how the racers deal with this?

[chipko]

The cat racers use surface penetrating cleaver props as far as I know.

Us mere mortals should find running a cupped prop helps and some fit doel fins. Interestingly some of the small cat manufacturers recommend cupped props and I’ve noticed in some promo videos the motors often sport doel fins.

[Fenlander]

Ahh funnily enough should the Elling under-toob fail to fully stop this problem I have a pair of fins hanging in the garage that were on my previous Tohatsu 9.8 2-stroke 10yrs ago. It came with them but never liked their effect.

[Limecc]

Originally Posted by smallribber

I must admit that looks very nice and a lot of fun. I think my 9.8 Tohatsu would be good on that.

I am tempted to add to my fleet.

Why do you need a fleet?

(Mod Edit)

[smallribber]

[QUOTE=Limecc;831142]Why do you need a fleet?


Need... Now that is an interesting word.... What do you need

Why the fleet because that is what I chose to spend some of my money on and quite satisfied to be honest. Got to spend it on summit cant take it with you.

(Mod Edit)

[Limecc]

Originally Posted by smallribber

Need... Now that is an interesting word.... What do you need

Why the fleet because that is what I chose to spend some of my money on and quite satisfied to be honest. Got to spend it on summit cant take it with you.

Nice position to be in and if your fleet isn't drawing mrsSmallribbers attention then your world's perfect.

[smallribber]

Originally Posted by Limecc

Nice position to be in and if your fleet isn't drawing mrsSmallribbers attention then your world's perfect.

She is happy with what we buy it is a non issue

[chipko]

Bit of an update. Not managed to get the little bugger wet, in fact has not even left the bedroom yet, but been busy fettling, as you do.

Fitted some seriously heavy duty leftover Russian cranked transom wheels (originally intended for our now ex. T38), added towing eyes, and sealed all new and existing transom holes plus dodgy factory fitted auto baler. Will swap out the rather small stock wheels with some large 16” jobbies from the spares box.

Also been busy concocting a lightweight method of handballing said rig across site, through dunes and over soft sand to the water. Already possess galv. launching trolleys, but a tad heavy so fabricated a timber gizmo (which clips into transom wheel mounts) and will take the strain off the bow ring whilst hauling through dunes. Also knocked up a lightweight combi dolly/motor trolley to take the nose weight out of pulling. Quick release tow ball for outboard storage mode. Still need to add some foam protection, and the boat of course!!

No bleedin idea if any of this lot will actually work, but hoping to find out sometime next week or so, weather god’s permitting.

[chipko]

So little ‘Flipper’ all set to go on its maiden voyage. Super sunny but freezing cold here ‘up north’ and just waiting for the 1.5m surf to calm down a tad to give us a sporting chance of it not living up to it’s name launching. Feels super light, even loaded with kit, and optimistic gonna be ok to haul through the dunes on the diy trolley. Now itching to see how it goes with the tiny 3.5 motor or even if it actually floats!

Also pulled the rib out of storage yesterday, but to be honest more excited to get the little ‘cat’ out on the water first...sad or what!

[Fenlander]

Looks like it will be great fun. I was actually showing Mrs F the larger image from the other channel and she was admiring the trolley setup. Is that the one on offer in Aldi this week?

[chipko]

Originally Posted by Fenlander

Is that the one on offer in Aldi this week?

Afraid not, had it a good few years. It’s a lightweight aluminium Clarke sack truck from Machine Mart.

https://www.machinemart.co.uk/p/clar...um-sack-truck/