Where to put fuel and battery (weight distribution on RIB)

wild.coast

Cadet
Joined
Sep 17, 2022
Messages
20
18ft alu RIB with 50hp Yamaha. Current have the fuel tank and battery jammed right in the back by the transom. Looking to clean up my wiring and add a proper fuse box and stuff, so wanted to move the battery somewhere else with more room - curious if anyone has any advice!

I've heard that shifting weight forward helps a lot with handling and weight distribution. The boat has two bench compartments: one is the bench the driver sits on and another bench near the bow, pics:

pic1.jpg
pic2.jpg
Apparently I don't take photos of my boat so you get some sea cliff climbing action! :p

The obvious/convenient place is the rear 'driver seat' bench, putting the battery beside where the driver would be sitting. I'm just thinking maybe it doesn't shift weight forward much. The front bench is a bit more awkward, smaller entrance and would mean I would have to make super long battery wires to reach the outboard, not sure if that's a problem. The other option is to put the fuel tank at the very front, but again, would need super long fuel lines, not sure if any issues/problems with that? In short, easiest and most convenient is the rear bench but if it's worth doing all the extra work to shift it all to the front then I want to know!

Thx so much!
 

crazy charlie

Vice Admiral
Joined
May 22, 2003
Messages
5,501
Weight distribution on my Zodiac is opposite side of where I sit while navigating.Weight forward will help got you on plane faster but give you a lot more drag when not planned off.Charlie
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,669
That's only a 50 horse engine. Your operating envelope is probably 0 to 25, maybe 30 MPH. Since you have a "helm", you can stand more weight aft than you would want with a "tiller" control system. Rule of thumb for me, with any boat, is play with everything you can touch and stop when you have achieved the maximum desired result.
 

wild.coast

Cadet
Joined
Sep 17, 2022
Messages
20
I was playing around with weigh by getting a friend to move around the boat. Noticed that having someone sit at the front actually slows the boat down! Drops from about 20 knots to 18 knots when the person moves towards the front. Odd! Any ideas?
 

Texasmark

Supreme Mariner
Joined
Dec 20, 2005
Messages
14,669
I was playing around with weigh by getting a friend to move around the boat. Noticed that having someone sit at the front actually slows the boat down! Drops from about 20 knots to 18 knots when the person moves towards the front. Odd! Any ideas?
Moving forward put more of the hull in the water. Reduction was caused by added friction with the water.

Different types of boats usually have different hulls to support the functional design of the boat. Example is the Bass Boat with the "Pad" hull. The hull has a pretty good "dead rise" along the hull and somewhere around the middle and extending to about 6" ahead of the transom is a flat surface 10" more or less wide. With their high HP engines, they have enough power to get the boat to a speed whereby the correct Power Trim setting will only have the "pad" touching the water's surface and will see them make 65 MPH in some cases. Reason is 2 fold.....hull to water contact reduction due to decreased contact area, and enough HP to cause that to happen.

Had you had more HP and or Power Trim and Tilt, with an angle adjustment with the trim button may have solved your reason for someone moving forward.
 
Top