Never Drove a Boat Before?

Joined
Oct 23, 2015
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16
I recently boat my first "real" boat. It's a 1989 Bomber bass boat 15ft with a Mercury 115 Inline 6. The biggest outboard I've ever operated is 5hp mercury tiller so it's definitely a different breed of dog. I took it out for the first time yesterday and wasn't really sure what to do as far as trim and plane and all that stuff. I played it by ear and when going about 3/4 throttle the bow was bouncing up and down..I freaked out and slowed back down to idle. Also it seems like it's either idle or wide open..no in between. After planing off I'd be flying and want to slow down but as soon as I backed off the throttle the bow would raise back up and I'd sit down in the water. I want to go fast but not scary fast. How can I remedy these issues? I know I have a 115 hp but all I want to do is about 30mph or so until I'm comfortable.
 

roffey

Commander
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Nov 22, 2012
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2,184
you have to trim the motor all the way down. I think your problem is the motor is trimmed up for speed or open throttle. When you back the throttle off you should trim the motor dowm.
 

thumpar

Admiral
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Jun 21, 2007
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6,138
If it is porpoising you need to trim down. Mine is good full up most of the time but when I am in waves or at cruise speed I trim down a bit.
 

hosteter

Petty Officer 2nd Class
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Oct 29, 2015
Messages
114
Yea your trim is too up when the bow is bouncing up and downn.trim it down and it will be better.
 

roscoe

Supreme Mariner
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Oct 30, 2002
Messages
21,657
what is the max hp rating for that hull?

It might explain a lot.

A 115 weighs 100 lbs more than a 75 hp motor, and puts out 50% more hp than the boat appears to be rated for.

That will make for a scary ride, and all sorts of handling issues, as well as being illegal in some states.

1989 Bomber by Commander 150

The 1989, 150 is a 15 foot outboard boat. The max rated horsepower of this boat, as listed by the manufacturer, (according to records we have) is 75 hp . (boatspec.iboats.com )
 
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southkogs

Moderator
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Jul 7, 2010
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^^^ That was my first thought too ... check your MAX HP on that hull. The boat might be tellin' ya' she's running kinda' hot :flame:
 

WIMUSKY

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When starting to get on plane, make sure the motor is trimmed all the way down/in. Once on plane, back off on the throttle to the desired speed. Trim the motor up "a little", it may be touchy so you might only have to tap the up button a couple times. If the wheel becomes easy to steer, stop. If it starts to bounce, hit the down button until it quits. Maybe with that setup it will run fine w/o trimming it up at all...... Trimming by ear in this situation wont help. You need to trim depending on what the boat is doing.....
 

gm280

Supreme Mariner
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Jun 26, 2011
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14,585
Some great advice presented here. And I agree with the trim all the way down and get the boat to plane out first. Then lightly tap the trim up until it rides smooth and happy boating. Once you get the hang of it, you will know that best of both the throttle and trim positions for the different speeds. I know how you feel. I went from a 9.8 HP Mercury on a 12' FeatherCraft boat to a 115 HP Mercury on a high performance bass boat. Totally different world. But it didn't take long before I could drive it without worry. I also suggest you read the water well out in front of you when moving fast. A cross breeze or wave action can be iffy if you don't account for it. High speed boats are not for everybody. JMHO!
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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on boats with power trim, I usually keep my thumb on the rocker. slow down while trimming down, accelerate while trimming up. you will get the hang of it.

trim all the way down for holeshot, bring up slightly as boat comes on plane.


I agree the 115 on a 15' is way overpowered
 

scipper77

Commander
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Sep 30, 2008
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2,106
Sounds like were talking Merc "Tower of power" motor. Those things are massive. What might help more than anything listed here yet is to get some ballast in the front of the boat. This is one of those rare cases where adding more wait to the boat may actually make things a whole lot safer. (Or redistributing weight). The official view of most members here is that safety really is the most important thing when boating. It's not just that we want you to be safe, it's that we spend time ourselves on the water with our families and would never promote other boaters to endanger everyone else.

Also, look into the pros and cons of a "Whale Tail".
 

sphelps

Supreme Mariner
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Nov 16, 2011
Messages
11,429
Smart tabs may help also .. As others have said a 115 may be a bit over powered ... When it starts to bounce trim down as was mentioned .. I would recommend wearing your pfd also ... The smart tabs will allow you to plane at lower speeds also ...
 

jayhanig

Master Chief Petty Officer
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Jun 27, 2010
Messages
836
advice-----take the boaters safety course. i learned quite a bit from it

While I agree that you can learn a lot in the basic boat safety courses offered by the Coast Guard Auxiliary or the Power Squadron, they don't really teach much by way of nuts and bolts boat handling. I ended up teaching myself after having taken a safety course from both organizations. That isn't to say they're not worthwhile; they definitely are. It's just that there's more to it than what they address.
 

thumpar

Admiral
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Jun 21, 2007
Messages
6,138
Not that a safety course is a bad idea but Jay is right about the actual handling of a boat. The safety courses teach you everything you need to know about safety only. Luckily my grandpa got a boat and slipped it when I was 5. I started doing all the docking and driving when I was around 12.
 
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NYBo

Admiral
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Oct 23, 2008
Messages
7,107
Yeah, there is no way for a group course to teach you how to handle your particular boat in the waters you boat in. Way too many variables. This is where a experienced friend who is willing to go out with you is invaluable.
 

BigManDan72

Petty Officer 2nd Class
Joined
Sep 20, 2015
Messages
101
I don't think the boater safety course recommendation was intended as a means to teach the OP how to operate his specific boat. I think the basic statement is:

Boat safety training = Good thing to do for a new boater
 

boatman37

Lieutenant
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May 14, 2015
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1,273
^ yes. sorry for the confusion. based on the title i was recommending the safety course
 

61mysteryboat

Petty Officer 2nd Class
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Oct 22, 2015
Messages
104
I can't believe I'm saying this, but this may actually be a situation where less is more . Wow, did I just say that?
 
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littlerayray

Lieutenant
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Feb 17, 2013
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K first congrats on the new to you boat 2nd you don't drive a boat you pilot a boat thirdly take the advice of all the post we want you to be safe not just for your sake but for everyone's
 
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