First rib.... advice appreciated

[Smagu]

Hello folk. Great forum with loads of helpful advice.

I’ve been generally into boats for a long time. Ever since doing an rya course. I’m handy with spanners and already fix jet skis (for which I have no love)

Always wanted a rib.

A colleague of mines father is selling his rib. It’s a circa 2003 Humber he believes it’s 5m but I think it’s 6. (It’s definitely not 5!). My question is it’s powered by a 2 stroke 60hp (similar age to boat), which I feel is abit under powered! Seems like a good deal tho includes gps and fish finder. Good trailer and a backup 4hp for £5000.

Im not looking for a super fast rib. Am I getting first boat jitters or are these valid concerns in your eyes?

[Ferryman]

There are various ways to measure a rib but it should be from the bottom of the transom to the front of the tube at the bow.
IMO it's underpowered, for a 5m you'd need 70hp and a 6m, 90hpish for any kind of load.

[Fergus3060]

I had a Humber 5.5 with a 60hp 4 stroke. Would get 3 adults to 30kts easy enough, but would begin to struggle with much more load. Great fun but I did always want something a bit bigger that could take a bit rougher sea. I now have an Arctic 22

[Pikey Dave]

Personally, my rule of thumb for RIB power is 15hp/m as an absolute minimum. If you want to have some fun with some pax on board, double it[emoji6]

[InlandAlex]

What HP you actually need and what HP you want are always a source of contention.

I mainly use ribs around the 5.5m mark, for which around 90 HP is the most common size for a balance of decent speed and power. However, a 5.4m searider with a 50 on it will still do 27knts 2 up.

A 6m RIB with 60hp is too low though, I’d have a minimum 90 on it.

Dave... by your rule the absolute minimum HP for an SR4 would be 60, and the “fun” level would be 120. The boat is rated for max 50. I take it your formula is mainly aimed at bigger boats? [emoji6]

[Searider]

Originally Posted by InlandAlex

Dave... by your rule the absolute minimum HP for an SR4 would be 60, and the “fun” level would be 120. The boat is rated for max 50. I take it your formula is mainly aimed at bigger boats? [emoji6]

I always thought that the 50hp on my SR4M was too small!

[Pikey Dave]

Originally Posted by Searider

I always thought that the 50hp on my SR4M was too small!

Wasn’t there a guy on here who put a squirrel gas turbine on a SR4?[emoji848]