The Guppy ...

[Andy B]

11mph,
That's healthy out of a Mariner 3.3hp

[neil h]

that's really quite respectable... I assume it was planing?

[mattswan2512]

Same as neil......did it plane??????

[Paul]

Great to see you got the Guppy out on its maiden voyage Donny
Can't wait to read about how your launching modifications performed, your views on how the Guppy handles and performs
Seems like you enjoyed yourself with the 14 miles recorded on the screen

[The Gurnard]

Thanks again for dropping by guys..its appreciated. to answer some questions...

Before starting the “Guppy in the Goil” threat..perhaps it is worth adding a quick summery of my first impressions. Do keep in my ..its only my opinion.. and is based on my own particular requirements .. and my experience with small boats.

Portability.

I debated with myself before the purchase.. on whether to get the smallest of the F-Rib range (275) ..or the next size up (330)..which would understandably handle bigger seas. There is not much difference in price..but the weight concerned me a little at 36kg(275) against 43kg(330). I am now very happy I went for the smaller size. I can lift it and carry it very short distances myself. I personally would have struggled with the 43kg boat. Being able to move the boat myself was a number one priority. Both boats would fit in my car no problem. They do take up slightly more space than a rolled up inflatable of similar size.. but that is off set by the size of outboard required for reasonable performance. I have plenty room in the small size boat too...but I am alone.

Outboard Performance.

I was delighted to be able to plane at 11 MPH with my Mariner 3.3HP . The outboard is a two stroke and 10kg.. so can be lifted with one hand.. and stored in a small space in the car. I did 20 miles trip using 4 litres of fuel.

I couldn’t get the F-Rib to plane at the start of the day.. simply because I carry a fair bit of gear with me.. it happily went 6 Mph on half throttle of the Mariner 3.3. That will be my normal operating speed..as I don’t want to thrash my engine.

I unloaded the boat ..so only myself..anchor.. fuel ..and outboard were left in it. It planed every easily at WOT and came out the hole in around 10-15 meters.. I was sitting forward..but there was no need for precise balance. I didn’t try trimming the outboard either..so performance may improve slightly with tweaking.

Sea Handling.

It was a calm day.. although the wind freshened in the afternoon. The highest waves were only around a foot high..and as is the manner of waves in a sea loch..close together..some waves were just showing a tip of white on their crest. In a following sea..the boat didn’t notice the waves. Beam on..I was impressed with the stability of the boat..but it is a wide boat for her size (1.6m) so not a surprise. Into the waves..it nodded gently..it certainly didn’t slam like the slat floor did. I will report on performance in rougher conditions when I encounter them.

I was very impressed by its handling and turning capability.. at displacement speed .. shovethe tiller to 90 degrees and the boat spins on it axis ..no side slide whatsoever. I have not had a small light boat do this before...so am delighted with that aspect. At speed..if you call 11 mph speed..it felt that it was on rails ..no flinching or swerving..no cavitation ..and no transom splash back.

It appears to be a very dry boat..well.. except when you discover its rear compartment half full of water. Yup..that happened..because I accidentally knocked the rear bung out.. it definitely needs a modification there ..but no big deal.

I guess that is all I can say at the moment..until I start pushing her to her limits. Im happy with 3.3hp power for my use..but will possibly look towards a 6hp next season. I think a 10hp may be a bit much for my normal usage.. if I want speed..I have my Quicksilver 4.3m and 25hp engine.

Would I recommend the F-Rib ?.. so far.. I am delighted..and would have no hesitation recommending them.. no boat is perfect..but this puppy is 150% perfect for my coastal inshore and sea loch use...when Im on my own

[The Gurnard]

I should also add that all the DIY improvements worked a treat ..so now I can refine them and add the finishing touches.

If I can manage a night off the Guinness.. a stitch in time will save nine ... now my F-Rib has a name

[Andy B]

Outboard Performance.

I was delighted to be able to plane at 11 MPH with my Mariner 3.3HP . The outboard is a two stroke and 10kg.. so can be lifted with one hand.. and stored in a small space in the car. I did 20 miles trip using 4 litres of fuel.

I couldn’t get the F-Rib to plane at the start of the day.. simply because I carry a fair bit of gear with me.. it happily went 6 Mph on half throttle of the Mariner 3.3. That will be my normal operating speed..as I don’t want to thrash my engine.

Interesting,
I find with my 3.3 Mariner that the last third of the throttle was just more noise!
I wondered at the time if it was because the sib had hit it's wall at 6mph and the 3.3 just didn't have enough power to push through it?
My 2.9m sib was never going get over the hump and plane out with my 3.3hp.
Seems the hard hull in the F-Rib proves just how much drag there is present with an "Air Bag"

[The Gurnard]

Hi Andy..perhaps your throttle adjustment is set different to mine ? I know there is quite a difference in mine between half and full.. although as you mention..the last wee bit before it hits the running rabbit stop ..doesn’t seem to do much on mine either...but its only a fraction of the travel..probably around an eighth or less.

I was hoping I had a photo with wake showing the throttle on half setting..but to get the photo..I normally just shoot the top of the engine. I was cruising on half throttle out in loch Long for the full duration of that leg of my test..this is the wake I get at half throttle around 6mph

This one by luck..I have the throttle at the running rabbit position and you can see it. You will also notice the displacement wake is larger and the water churns more..but in reality the boat doesn’t go any faster..which is why I find best going back to half..it saves quite a bit of fuel..for very little loss in speed. This is when I was trying my best to get the loaded boat on the plane..but it wasn’t for it. it was doing about 6.5mph ..so a lot more fuel to kick up water and little forward momentum.

Of course.. a wake from the boat on the plane is completely different ..because its now skimming along the top of the water..rather than pushing a bow wave. The displacement wash wave has now gone..and she is skimming.. at full throttle ..but no baggage in the boat so a lot lighter...going around 11 mph

I could never get my other wee sibs on the plane with me aboard ..and with the 3.3HP. Smooth hulls are very much more efficient than fabric hulls.

[Andy B]

Here's a short video of my 3.3 at full rabbit
Moving the sib along well with 2 people onboard, but a lot of noise and nowhere near getting it to plane...

[neil h]

I have a Mariner 3.3 just like it... only mine needs fixing, it started up yesterday, but does not want to rev. Just another job to do.

Impressed with your new rig Donny!