Cruising speed

[Fishop]

Wondering what you guys cruising speed is at?

mine sits on 20-21 knots (gps speed) at 3/4 throttle (4400rpm). 

Reason I ask is that I eventually want to take it out to the reef but the closest reef is around 60kms away so would take over an hour and a half each way.

If people average 30+ knots cruising speed, Wondering if it's worth spending the money or not to cut the travel time down a bit. 

[fragmeister]

Hi Fishop,

What rig do you have?

I am not familiar with Brisbane marine conditions but I was wondering what sort of prevailing conditions and boat you might have that would allow 30 knots.

It would be interesting to hear what others contribute to this so thanks for the post.

Cheers

 

Jim

 

[Fishop]

On 26/04/2017 at 4:20 PM, fragmeister said:

Hi Fishop,

What rig do you have?

I am not familiar with Brisbane marine conditions but I was wondering what sort of prevailing conditions and boat you might have that would allow 30 knots.

It would be interesting to hear what others contribute to this so thanks for the post.

Cheers

 

Jim

 

Sorry I am up in the Whitsundays so conditions are generally windy but I was referring to a calm day with glassy conditions. 

I have a 5.6m carribean old late 80's fibreglass boat.  It's also got a full size canopy on top which drags a bit in the wind. 

It's just on the cusp of being underpowered as I've met a previous owner who had a 140hp on the back. It's now got a 90hp. Gets on the plane but it's pushing 3/4 throttle to keep it there which is why I was wondering if that's a bit slower than usual. 

[fragmeister]

Ah ha... that makes more sense.

I am no expert but it certainly looks like it may be under powered if it needs 3/4 throttle to get up on the plane.

 

Cheers

 

Jim

 

[Fishop]

Also has a 16p vengeance prop.  I can hit max rpm (5800+) with a full boat so if i went up a size in prop that might push my speed up a bit and lower the rpms for planing??  Have I got that right?  Might see if my local Merc dealer will let me trial a couple of different props.  

Currently with 4 people onboard it sits at 4200-4400rpm and 18-20 knots to keep it on the plane.

Edited May 1, 2017 by Fishop

[Fishop]

Spoke to Solas props. Guy there said vengeance props are known for slippage. Thinks a 16p vengeance is worth a 14p solas prop and recommended me upgrade to at least a 15p Solas as I am hitting max rpm with a loaded boat so the prop sounds a bit small

Anyone also heard of vengeance props being know for slipping or is he maybe biased a little. 

 

[PaddyT]

Doubt you are going to solve too many probs with a new prop-your boat is underpowered pure and simple , especially if you load it up with fuel /four people and all their gear , call a Caribbean dealer and have a chat with them- there is a mob in Sydney who've been selling those boats for over 30 years and they would be familiar with your model I would imagine

[Fishop]

2 hours ago, PaddyT said:

Doubt you are going to solve too many probs with a new prop-your boat is underpowered pure and simple , especially if you load it up with fuel /four people and all their gear , call a Caribbean dealer and have a chat with them- there is a mob in Sydney who've been selling those boats for over 30 years and they would be familiar with your model I would imagine

Cool thanks for the tip

[GoingFishing]

I am no expert but id have to agree with PaddyT. You may want to consider upsizing your motor.

On my boat my cruising speed has me sitting at 3500rpm and whilst i could crank it up to 4500 or more id only get a marginal increase in speed so overall you get best bang for your buck at cruising speed. 

[JonD]

I run my rib pretty hard in rough conditions, it just rides better with more speed. Unfortunatly I need to run at 4800-5000rpm to run at 45 kmh, if I drop to 4500 rpm 37 kmh the ride is nowhere near as good. My outboard Max's out at 6300 and according to my mechanic running at 5000 rpm isn't going to harm it.