Should I add a foil or is it me?

[rtgnyg]

Hey all, Im a relative noob when it comes to driving a boat. Ive gotten used to the boat handling poorly when a slow speeds and feels real good when on a plane. Problem is I plane out at about 21 mph. I have younger kids that I would like to take tubing but would like to keep the speed down. Also when I have people in the bench seat in the back the boat shoots to the moon for a good long time before planeing out. So I've searched and gotten a hundred different opinions only foils and tabs. I understand tabs would be better but really trying to stay away from drilling holes in my boat.
I've got a 18 foot starcraft with a F115La fourstroke. My question is should i just drive the boat and get used to it? ( I definitly plane quicker the more im willing to dig into the throttle) or would a foil actually help.
Also the prop is a three blade that I'm guessing is a stock prop?

Thanks for any insight.

 

[smokeonthewater]

Four blade stern lifting prop and smart tabs.

Just get over the holes in boat thing.... They are really really worth it.

Don't waste ur money and time with a foil.

 

[southkogs]

A lot of factors come into play when getting a boat on plane: weight, prop-type (pitch/diameter), HP rating, etc., etc.

Tabs are a popular (and pretty good) option, but other simple factors may be playing in. Do you have trim available and does it help? What HP is the boat rated for (115 sounds a bit light for an 18)? What RPM and speed are you getting at WOT.

Tabs may be it, but if you're not wanting to drill there are a few other questions we can ask to see.

 

[Alumarine]

Is this a fiberglass or aluminum starcraft?
If it's aluminum I'd guess your motor is not trimmed in enough.

There's no harm in giving it ample throttle to plane quickly and then backing off.
That's much better than keeping the bow pointed up for a long time.

 

[NYBo]

Welcome to iboats!:welcome:

Not using enough throttle is a common mistake. See if nailing it gives you the performance you need/want. Cost: $0. Driving with the nose pointing to the sky isn't very safe!

We periodically have the foil vs tabs debate here, with many sayng that a foil is a "band-aid" that doesn't address the "real problem." I contend that a foil is no more of a band-aid than tabs. The bottom line is whether either one works for your situation. Tabs almost always work but cost considerably more. Foils are more of a gamble. I've been satisfied with foils but YMMV, as they say.

 

[airshot]

If you stab the throttle hard and get on plane....then slowly back down until the boat comes off plane....still 20 mph? Sounds like you have a very heavy engine on the back of that 18' so weight, trim will be everything. On stern heavy boats the only practical way to get on plane quickly is jab throttle hard to get on plane then reduce throttle to speed that just supports the hull on plane. Typically should be around 16-18mph if weight is distributed correctly. I had an 18' starcraft and it would plane at 15mph...just barely but needed to hit throttle hard to get it up then back it down to desired speed. Bringing the throttle up slow will cause the hull to plow and eat up your precious fuel.

 

[rtgnyg]

thanks for all the replys. Its an 18 foot starweld which is aluminum. As ive gotten more comfortable, I nail it and it does plane out much quicker. I then back down and it seems to stay on a plane until about 18 or 19mph. If possible id like to be able plane lower for pulling a tube and still having good control.
Im thinking its stern heavy as it has a full bench in the back and when anyone is back there it tends to porpise alot once on a plane. around 30mph. If the people in the back move to the front or middle it lessens significantly.
It does have electric trim and i trim it all the way down when this happens.

 

[Alumarine]

When it's on the trailer check to make sure the trim is able to go in as far as possible.
There may be a pin that stops the motor to soon?

 

[smokeonthewater]

Put the smart tabs on it.... Best $130 you'll ever spend on your boat!

 

[airshot]

You may need to change your seating or alter the number of persons on board......weight distribution is "everything" on an 18 boat. I would not expect to go much under 16 mph before dropping off plane with the big motor you have, however it is possible if you move enough weight around and the hull does not have any hook to it. On my boat I removed the rear seats on each side of the engine and moved them forward to have three seats in front of my engine (I/O) and the balance improved many times over, my 22' will plane at 16mph with ease in calm water, but still need to get up on plane then throttle down to go that slow.

 

[bobdec]

Pulling tubes w/young children at slow speed is a challenge. I found trim tabs helped me hold a plane at somewhat lower speeds. But it has a lot to do with your boat design, different setups plane at different speeds. W/O my tabs down my Proline's hull will not hold a plane below 23 MPH. Any speed between 7 MPH and 23 is a waste of effort and fuel with the stern just plowing water. The tabs down allow me to hold plane at about 19-20 an improvement, but a fuel eater. As an example the above poster has a boat design that planes at 16. Also when if your just running at the minimum speed to hold a plane it can be a very tiring day on the water trying to hold that position. It's like running an inlet that doesen't end. Also if your running in displacement speed below planing speed the stern down and bow up is almost a certainty. Rearranging the load will help a bit. When pulling young ones I find myself constantly having to add/remove throttle to overcome the slightest conditions that will drop off of plane and cause a fast drop in MPH and crappy handling.