How fast will my rib go roughly?

MrLiam · 27 July 2011, 13:22

Hello how fast will my valiant v490 with a 60hp mariner 2 stroke. With 2 people and 50l ish of fuel on calm water.

longjohn · 27 July 2011, 13:30

30-35knots at a guess

mattfx · 27 July 2011, 13:47

Hope you dont mind me hopping aboard this thread.... could I ask the same question, I have a Zodiac Start 400 Rib, with a Mariner 15HP 4 Stroke, all in good order. With two adults, two little ones and 25 litres of fuel - any ideas of top speed (and indeed range if anyone feels so inclined to guess)?

We have so far only bimbled around rivers so never got above around 6 knots!

Thanks
Matt

MrLiam · 27 July 2011, 14:03

Quote:

Originally Posted by longjohn

30-35knots at a guess

Wow thats awesome now all I need is decent weather but hopefully saturday should be good.

Searider · 27 July 2011, 15:50

Much faster when it's smoothly. Roughly can be a bit hard work!

georgieboy · 27 July 2011, 17:16

Quote:

Originally Posted by mattfx

Hope you dont mind me hopping aboard this thread.... could I ask the same question, I have a Zodiac Start 400 Rib, with a Mariner 15HP 4 Stroke, all in good order. With two adults, two little ones and 25 litres of fuel - any ideas of top speed (and indeed range if anyone feels so inclined to guess)?

We have so far only bimbled around rivers so never got above around 6 knots!

Thanks
Matt

Matt,

i have 3.5m with 15hp. with me and the missus, full tank of fuel and some fishing gear we get around the 20mph mark with it wide open. sometimes nearly 25mph but it needs to be really flat.
so i would guess that with a little more weight than mine plus the exra length it would be very slightly slower.

george

Jorgos · 27 July 2011, 17:24

28-31 knots

Poly · 27 July 2011, 18:25

Quote:

Originally Posted by MrLiam

Hello how fast will my valiant v490 with a 60hp mariner 2 stroke. With 2 people and 50l ish of fuel on calm water.

It will depend on various factors, prop selection, engine trim (and if you have PTT so can modify on the fly - or have to accept a compromise) etc. I'd have thought it shouldn't be too much trouble to break 30 knots, and even 35 might be beatable if you get everything in your favour.

Quote:

Originally Posted by mattfx

.... could I ask the same question, I have a Zodiac Start 400 Rib, with a Mariner 15HP 4 Stroke, all in good order. With two adults, two little ones and 25 litres of fuel - any ideas of top speed (and indeed range if anyone feels so inclined to guess)?

I have a similar sized boat with 20HP 2 stroke, it tops out around 22 knots, so I would guess you will be in the 18-20 knots range. With 1 adult but plenty of kit on board in flat calm conditions I can get about 60 NM from a standard 25L fuel can, cruising at over 18 knots. You should manage similar - but obviously ensure you carry enough spare especially while you determine this for yourself.