Inflatable boat size.

[Alicatt]

We bought a 2.7m air keel dinghy but not used it yet, we have a Honda 2hp outboard for it, davits are in the garage waiting to be fitted, one needs a new spring on the ratchet pawl and the davit mounts which are on the boat need to be drilled to take the davits.

Anyway I had a play around in the pool with the dink...

https://imgur.com/Cq6yR7J

 

[Chiara’s slave]

If you can't use a trolly there are wheels that you can attach to the transom of an inflatable they lift up out of the water when motoring. Also given that you have to lift everything and transport it then the weight of the engine is going to be your limiting factor in that department which in turn will limit the size of the inflatable.
You don't say which waterways you are going to be using them on but be aware their are usually speed limits on rivers and even lakes so again the size of engine might not be that critical.

This was our solution in the same circumstances. Put the engine on at the car, stick the gear in, use it as a wheelbarrow. I reckon you’d be fine with up to about 6hp used like that. And I would very much have the biggest I felt I could deal with.

 

[Baggywrinkle]

I currently have a 2.5 meter air floor inflatable , ( no keel. ) with a 3.3 Hp, that I use on a smaller lake/river. Roughly 200-250 meters wide and 6.8 km long. I want to venture to a much bigger lake to explore islands and do a bit of fishing. This lake/river is probably 2.5 km wide and 100s of km in length and apparently can get very choppy . What size inflatable sib and motor would I need to venture into this bigger body of water safely .I know it's subjective and everybody has a different opinion but I'd like some suggestions. ?? Or is it solely dependent on wind conditions. I don't have the option of a fiberglass fishing boat as I have no where to keep a boat on a trailer.

Perhaps @Bigplumbs will be along ... he has an extensive collection of inflatable boats which he keeps adding to, sure he would be a good source of advice.

 

[Fr J Hackett]

Perhaps @Bigplumbs will be along ... he has an extensive collection of inflatable boats which he keeps adding to, sure he would be a good source of advice.

All trailered iirc

 

[Cerebus]

I posted (or thought I did) a long post about covers / dodgers and hard flooring but it seems to have disappeared to be replaced by something else quite irrelevant, so I have deleted it and cannot replicate the long post I thought I posted.

Others have posted good info, so good luck.

 

[ridgy]

I would just use what you have. Obviously bigger is more space and bigger engine is faster getting to where you need to be but on your big lake you're never more than 1.2km from land.
You're not going to make a quantum leap in terms of safety or comfort going from 2.5m to 3 or 3.5m.

Just remember that waves are created by wind so no wind = probably no waves so more important than the boat is the weather.
The further the wind blows over the water the bigger the waves so if its blowing down the length then much worse waves than if it's blowing across.

Download a proper wind app on to your phone e.g. Windy.
Blue = fishing
Green = probably no fishing
Brown or red = definitely no fishing.

One of my other hobbies is fly fishing, often on rented boats on large reservoirs and those are usually heavy 4.5m fibreglass fishing boats with 5hp outboards and even green on Windy you're getting wet if you have to motor upwind. You will want to make a seat with a back that can be attached to the dinghy seat.

 

[Cerebus]

I currently have a 2.5 meter air floor inflatable , ( no keel. ) with a 3.3 Hp, that I use on a smaller lake/river. Roughly 200-250 meters wide and 6.8 km long. I want to venture to a much bigger lake to explore islands and do a bit of fishing. This lake/river is probably 2.5 km wide and 100s of km in length and apparently can get very choppy . What size inflatable sib and motor would I need to venture into this bigger body of water safely .I know it's subjective and everybody has a different opinion but I'd like some suggestions. ?? Or is it solely dependent on wind conditions. I don't have the option of a fiberglass fishing boat as I have no where to keep a boat on a trailer.

I found a bit of my post.

No idea if it is of use.

Here it is:

Does you sib have a solid floor?

It makes a difference to how the ‘boat’ performs (I have one without a solid floor and one with).

You know more than I do because I do not know what water conditions or wind conditions you experience.

Simple answer is to increase size of sib perhaps?

Your constraints appear to be that you need to pack it up at end of the day and have no trailer; so size means it must fit in back of car?

Sibs are very stable (so I have read and experienced, but can be wetter than solid tenders).

Can you buy or make a cover or canopy to keep water out and make trips more comfortable?

The canopy could be raised via tent pole type things upon a hard deck or floor and have transparent panels

 

[ashtead]

I think you have basically three problems namely weight of boat - looking at quicksilver by way of example as we have one it’s over what you weight wise say u might manage . 2 weight of engine -unless you can pick up a 2 stroke engine even lugging say a 6hp yam is to much without a trolley. There is an f rib but would a folded hull fit in land transport? So unless you take up some weight training (or buy a set of wheels or collapsible trolley then the bigger hull plus large tubes might be a strain. Could you find a plastic dinghy you could roof mount or transport a folding F rib say Have a nifty roof rack to lower it? 3 the bigger boat might not be that much drier -even at 3.1 m you only need some wake rib type to pass you and the sib will be damp- in fact when in Alderney on occasions we have used the water taxi as we thought the use of our sib was too wet.

 

[munster1967]

This was our solution in the same circumstances. Put the engine on at the car, stick the gear in, use it as a wheelbarrow. I reckon you’d be fine with up to about 6hp used like that. And I would very much have the biggest I felt I could deal with.

Yes. I think the wheels on the transom are the way to go. Then I only have to lift engine directly onto transom beside car.

 

[Chiara’s slave]

I think you have basically three problems namely weight of boat - looking at quicksilver by way of example as we have one it’s over what you weight wise say u might manage . 2 weight of engine -unless you can pick up a 2 stroke engine even lugging say a 6hp yam is to much without a trolley. There is an f rib but would a folded hull fit in land transport? So unless you take up some weight training (or buy a set of wheels or collapsible trolley then the bigger hull plus large tubes might be a strain. Could you find a plastic dinghy you could roof mount or transport a folding F rib say Have a nifty roof rack to lower it? 3 the bigger boat might not be that much drier -even at 3.1 m you only need some wake rib type to pass you and the sib will be damp- in fact when in Alderney on occasions we have used the water taxi as we thought the use of our sib was too wet.

As above, we used an air floor keeled SIB with wheels bolted on the transom for years. The 4hp outboard was no bother, we used to fit it and use the boat to move it. I’d have liked a bigger engine, but couldn’t justify the cost of upgrading. The boat was a Zodiac 2.7

 

[Chiara’s slave]

Yes. I think the wheels on the transom are the way to go. Then I only have to lift engine directly onto transom beside car.

It’s actually easier than a trailer or trolley, you don’t have to drag it up the hard and leave it. Our boat was 25 years old, a bit floppy by todays standards. New ones are pretty tight.

 

[munster1967]

I would just use what you have. Obviously bigger is more space and bigger engine is faster getting to where you need to be but on your big lake you're never more than 1.2km from land.
You're not going to make a quantum leap in terms of safety or comfort going from 2.5m to 3 or 3.5m.

Just remember that waves are created by wind so no wind = probably no waves so more important than the boat is the weather.
The further the wind blows over the water the bigger the waves so if its blowing down the length then much worse waves than if it's blowing across.

Download a proper wind app on to your phone e.g. Windy.
Blue = fishing
Green = probably no fishing
Brown or red = definitely no fishing.

One of my other hobbies is fly fishing, often on rented boats on large reservoirs and those are usually heavy 4.5m fibreglass fishing boats with 5hp outboards and even green on Windy you're getting wet if you have to motor upwind. You will want to make a seat with a back that can be attached to the dinghy seat.

Great stuff. Thank you very much. Great information there, especially regarding the wind app and direction of wind. I might put transom wheels on the sib. Then I could put a 5 Hp 2 stroke on her. Without having to lift the engine over any distances. My little inflatable is rated as a category c , but I cant imagine being out in 1.5 meter waves !!! In it.

 

[munster1967]

I think you have basically three problems namely weight of boat - looking at quicksilver by way of example as we have one it’s over what you weight wise say u might manage . 2 weight of engine -unless you can pick up a 2 stroke engine even lugging say a 6hp yam is to much without a trolley. There is an f rib but would a folded hull fit in land transport? So unless you take up some weight training (or buy a set of wheels or collapsible trolley then the bigger hull plus large tubes might be a strain. Could you find a plastic dinghy you could roof mount or transport a folding F rib say Have a nifty roof rack to lower it? 3 the bigger boat might not be that much drier -even at 3.1 m you only need some wake rib type to pass you and the sib will be damp- in fact when in Alderney on occasions we have used the water taxi as we thought the use of our sib was too wet.

Thank you for your reply. The answer seems to be to attach wheels to the transom and attach a bigger engine at the car. ! Maybe a 5 Hp 2 stroke. And go to a 3 meter sib.

 

[Chiara’s slave]

Great stuff. Thank you very much. Great information there, especially regarding the wind app and direction of wind. I might put transom wheels on the sib. Then I could put a 5 Hp 2 stroke on her. Without having to lift the engine over any distances. My little inflatable is rated as a category c , but I cant imagine being out in 1.5 meter waves !!! In it.

Not on purpose at any rate I’d be on the lookout for one with a keel, it makes quite a difference in the chop. But run with what ypu’ve got for the moment. Ebay and Amazon flog the wheels, as well as the usual marine outlets.

 

[munster1967]

Not on purpose at any rate I’d be on the lookout for one with a keel, it makes quite a difference in the chop. But run with what ypu’ve got for the moment. Ebay and Amazon flog the wheels, as well as the usual marine outlets.

Exactly not on purpose anyway. !! .
Yes I think a keel and the transom wheels and weather app will solve a lot of my concerns. Cheers.

 

[dunedin]

Not sure the type of your existing “SIB” but certainly one with an air floor and an inflatable section to create a V floor beneath it, is massively better than a flat floored version.
Decent sized lifting wheels are also great - but do make heavier and/or longer time to pack and reassemble.
Perhaps a second hand 2 stroke outboard might be lighter and more transportable than a 4 stroke of the same power.

But overall it is the conditions that matter more than the size of the water, I was recently sailing in the Atlantic West of Shetland and on the day the water was flat and could have paddled in a toy boat. A few days later I got seriously pasted in a 10 ton 12 metre boat in a much more “sheltered” patch of water, due to combination of wind and tide angles.
Check multiple weather forecasts and think about what the conditions might be getting back to base, before departure.

 

[KompetentKrew]

You'd probably be better asking on the RIBs net forums (can't remember the exact URL spelling) or the RIBs and SIBs group on Facebook.

But you would find huge difference if you upgraded to a 2.8m airdeck (I have a Honwave 2.8IE) and a Tohatsu 9.8 2-stoke engine (that specific one). This combo actually planes, giving much better speed and range. I can't say that's the best and most ideal combo for you (not sure how large you can go without a trailer) but I think you'll find planing eye-opening.

 

[munster1967]

Not sure the type of your existing “SIB” but certainly one with an air floor and an inflatable section to create a V floor beneath it, is massively better than a flat floored version.
Decent sized lifting wheels are also great - but do make heavier and/or longer time to pack and reassemble.
Perhaps a second hand 2 stroke outboard might be lighter and more transportable than a 4 stroke of the same power.

But overall it is the conditions that matter more than the size of the water, I was recently sailing in the Atlantic West of Shetland and on the day the water was flat and could have paddled in a toy boat. A few days later I got seriously pasted in a 10 ton 12 metre boat in a much more “sheltered” patch of water, due to combination of wind and tide angles.
Check multiple weather forecasts and think about what the conditions might be getting back to base, before departure.

My existing sib is 2.5 meter air floor flat bottom. Tubes 38 cm.
thanks for your reply. 'im currently looking at a 2.8 with a keel. 42 cm tubes. Yes I think having read the replies , the wind and conditions seem to be the most important consideration on this lake. And perhaps a set of transom wheels so I can put a bigger engine on , maybe 5 or 6 Hp.

 

[KompetentKrew]

You might find this thread helpful: 2.7-3m and 6hp solo advive - RIBnet Forums

 

[Iliade]

I have found that a 2.5m is quite adequate at sea, even in really very rough conditions (>F6, open water). But... It must have an inflated keel. That 2.8 sounds great. Ones with flat bottoms are considerably less effective at cutting through waves and generally wetter and less directionally stable. If only one could still get Avon's S250.

I would trust a good flubber more than many a yacht!

Do try to go on a handling course for <strikethrough>poor</strikethrough> exciting weather.