Will 3.5hp suffice?

mikesy · 14 May 2015, 17:42

Hi ,
I could do with some advice on whether a Mariner four stroke 3.5hp would be okay for a 3.2m Sib for inshore fishing up to half a mile out maximum and only in calm weather.
I've read conflicting opinions , some say a minimum of 6hp+ and others say less would be okay.
If you have any feedback based on experience rather than opinion, it would be greatly appreciated.
I don't expect to get on the plane but would like to think that I can get back to shore against the out going tide or an offshore breeze.
Thanks in advance.

The Gurnard · 14 May 2015, 18:06

You will need to provide a wee bit more information before anyone can answer that honestly. What speed is the tides in the area you intend fishing in..if they are strong tides..then the answer will be no..if not very tidal..then the answer will be yes.

If its round the Firth of Forth in good weather..it should do no problem at all. You will just putter around at displacement speed though.

I have done some major sea adventures with a 2.5hp engine..but I always check there are no strong tides on my route.

This is my 2.5Hp going up Mortimer's Deep..shipping channel on Firth of Forth.. just at half throttle too ..so I speak with experience. Just dont expect to go fast.

The Gurnard · 14 May 2015, 18:26

Another couple of examples..my 3.3hp at full tilt off Arisaig

And my 4hp four stroke...10 miles off shore at Ailsa Craig..however..I like to think Im experienced and know what Im doing..I know the capability of all my boats and engines..so don’t try 10 mile open sea crossings..yet

However .. Stay close to shore until you know your boat and engine capabilities.

I wouldnt go through the Cuan Sound with these engines though..and I would need to check tide flow under the Forth Bridge.. 3 knots tide is getting close to a no no situation

mikesy · 14 May 2015, 19:38

Thanks for the quick reply. I will be mainly fishing from skateraw at Torness, Eyemouth and Granton.
also a few of the sea lochs out on the west coast.

Mickhitchuk · 15 May 2015, 04:43

Hi, I have no where near the experience of the other posters, who clearly know exactly how far they can push there outfits, but from my limited experience of a Honda 3.2 it pushed the sib around fine but as it was not powerful enough to lift the front up on my 2.7 honwave, I had a lot of wash coming over the front which was a pain, so sold the Honda bought a Mercury 6 hp 4 stroke which worked great but I found the remote tank took up too much room, selling that now and getting a 5 hp 2 stroke tohatsu,only a couple of hp more but I found gives a bit of additional insurance in case you make a bad call

mikesy · 15 May 2015, 05:34

Thanks Mick,
I'll see how the 3.5 performs when the sea is calm. I'm hoping it will meet my needs as I don't intend travelling far ( I've been told the there is reasonable fishing close to my launch point ).
Hope the 5hp works out for you.

Mickhitchuk · 15 May 2015, 06:04

Hope all goes well and your outboard does the job, if not as I have found (on 3rd outboard in 12 months) once you have one it easy to sell and but another until you get your set up right, although I do get abuse from the wife when dumping another outboard on eBay that I have used twice
Happy fishing

blootac · 15 May 2015, 07:22

My little mariner 2hp 2stroke would push my heavy avon rover 3.1 with 2 very large adults and 1 not quite so large adult at 5mph in slack water.

The Gurnard · 15 May 2015, 08:34

Yup.. that sound about right Blootac.

Here is more proof of them being of adequate size in calmer waters without strong tides.. my 3.3hp will happly move a 4.3m sib weighing 108 kg + 52 kg outboard + 50 kg of luggage + 100 kg of skipper .. around 4 or 5 mph too.

Mick.. I cant say for sure as I don’t know your setup..but I would think the issue you had with the SIB’s nose being down..was more a trim issue than an engine power problem ?..but I could be wrong. Keep all weight in the back.. have the engine set in the right angle ..and the nose will rise..even with a 2hp engine

However I do agree that smaller SIBs are kind of “ wet boats “..regardless the engine size.

Gazzdid · 15 May 2015, 13:41

interesting, as I have a little british seagull 2/3hp engine I will be using to try the boat out with when I have it ready. I've been wondering how well it will push it along

mikesy · 15 May 2015, 17:04

Thanks Gurnard,
I'm convinced now it should ok .
Your 3.3 seems to get along quite well with all that weight, is it a 2 stroke?

The Gurnard · 15 May 2015, 17:17

Quote:

Originally Posted by mikesy

Thanks Gurnard,
I'm convinced now it should ok .
Your 3.3 seems to get along quite well with all that weight, is it a 2 stroke?

Yup..its a 3.3 two stroke.. 13kg weight..so light and small. The seago (small grey inflatable) is 2.7m slat floor..so doesnt plane.. but it wouldnt surprise me if an air floor version wouldn't plane with that engine and just me on board..?

The red boat at Ailsa Craig ..its a 12ft fibre glass job..around 200kg weight and a 4hp is the manufacturers recommended size engine for it..because it is a displacement boat

So saying all this..if you have not bought the 3.5hp.. I would suggest buying a bit larger. However ..if you already have the 3.5hp.. I wouldnt worry..its safe enough in the areas you mention you will be using it

The other good thing about it is... the fish dont seem to care what size engine you have.. and that appears to be your use main for the boat

kaman · 16 May 2015, 18:49

I remember I got my first Sib - a 3.3m Plastimo with aluminium floor.
I had a brand new Johnson 2.5hp 4 stroke on the back.
My old man nearly fell off his chair laughing when I told him I would be accompanying him sea fishing down to the Mull of Galloway.
"That'll no stir your tea" he scoffed!
Any ways we went out fishing and my old man kept a watchful eye from his boat to make sure my little set up was going to get me and my mate back to Port safely.
There are strong tides around this area as Luce Bay empties on the turn of the tide.
The 90 is kg Sib with around 220kg of personnel / gear did toil against the tide at tine but ultimately overcame the tidal currents - in the end.
I now use a Tohatsu 20hp 4 stroke on a 3.5 aluminium floored Honwave.
I use a 2.5hp Suzuki as a back up / trolling motor.
This is the identical engine (rebadged) to the Johnson engine I had on the Plastimo.
The Honwave has much bigger tubes and is considerably wider.
It is only 20cm longer than the Plastimo but much more buoyant.
Despite being considerably heavier than the Plastimo - the 2.5hp powered engine shoves the Honwave along much easier than it did on the smaller Sib.
I attribute this to the fact that the Honwave is more buoyant hence less drag.
In the Sub 4 hp class you are touch and as to whether your Sib is up to making headway against tide and wind.
Just make sure you don't overload it and be mindful of tide and wind etc.
I'm sure you will enjoy it.
My safety concious old man now goes out Sib sea fishing on my Honwave more often than he goes on his own boat.
He is now contemplating getting one!

mikesy · 16 May 2015, 19:05

Thanks kaman. I'll be keeping an eye on the weather and tidal reports.
Fortunately I am able to get out any day I choose so I'll be mindful of what's the state of the sea and wind. First few times I'll won't be too adventurous and make do with a couple of hundred yards from my launch point to see how the set up performs.
If the sea is calm l might go out a little bit further.
I'm not too bothered about speed but as you say as long as I can get back against the tide and wind then that will be good enough for me.
ATB

Locozodiac · 18 May 2015, 01:40

If you haven't bought the 3.5 HP engine yet, better go for a 5 HP instead, small in size, weight, will handle much better than any 3.5 which is a basic engine.

Happy Boating