Rib

[Wilko45673]

Hi I am looking at buying an RIB probably around 4.8 m to 5.5m. It will have 4 people on it most of the time sometimes more.

How much power is needed on the outboard to go around 25 + knots with 4 people in it? Also how much is speed affected with additional people? Thank you

[Lee argyle]

Originally Posted by Wilko45673

Hi I am looking at buying an RIB probably around 4.8 m to 5.5m. It will have 4 people on it most of the time sometimes more.

How much power is needed on the outboard to go around 30-40 knots with 4 people in it? Also how much is speed affected with additional people? Thank you

Go as big as your budget and logistics allow, four or more in a 4.8m rib will be very cosy...........
(Pic is a 4.8)

[Wilko45673]

Thank you for the reply. So would 5.5 - 6 m be good for around 6 people or less. And with probably 70-80 hp engine, how many knots would this be able to do.(I’m very knew you this so don’t know a lot) Thankyou

[Lee argyle]

Originally Posted by Wilko45673

Thank you for the reply. So would 5.5 - 6 m be good for around 6 people or less. And with probably 70-80 hp engine, how many knots would this be able to do.(I’m very knew you this so don’t know a lot) Thankyou

Definitely heading in the right direction, power wise I’d be wanting at least 100hp on the back especially if your 6m+,

[Wilko45673]

Okay that’s useful thank you. So I don’t want one that’s too big, so a 5.5 metre boat I think is good for me. If you know this, what power would give what speed based on 4 people in the boat please, or 1 person if it’s easier to workout?

[Lee argyle]

Originally Posted by Wilko45673

Okay that’s useful thank you. So I don’t want one that’s too big, so a 5.5 metre boat I think is good for me. If you know this, what power would give what speed based on 4 people in the boat please, or 1 person if it’s easier to workout?

Numerous factors affect boat speed - hull shape, boat weight, load, props, hp etc etc, my point is one 5.5m Rib might do 10 knots more than another similar sized boat, however the latter Rib will do 25 knots in any seas where’s the faster Rib might struggle in adverse conditions ( flat fast hulls ‘slam’ in rough seas, deeper v hulls are typically slower but ride better when it gets lumpy ).
Personally, if you haven’t got your RYA powerboat level 2 then do it - as much as the training you’ll come away from the course having a better idea of what craft /size you want, also pop down your local marina and look at different rigs, talk to the owners and if you get a chance go out on a few, you’ll soon come to you own conclusions on the right boat for you

[Wilko45673]

Okay thank you I will do that when lock down is lifted.