How important is that fin??

[boatasticaldave]

I have a merc I/O 165, on the lower unit under the prop is a fin extending downward. This is the fin that would get damaged a bit, say if you pulled your trailered boat out of the slip and forgot to raise the unit first. Not that i would ever do that....uh...ya but lets just say you damaged it a bit. How important is this to the boating experiance? :facepalm:

 

[Bob_VT]

Re: How important is that fin??

Important to protect the prop. There are repair/replacement skegs available in the iboats store here http://www.iboats.com/Boat-Parts-Ac...ywords.skeg--searched.1--session_id.665198906

 

[MH Hawker]

Re: How important is that fin??

Would depend on how much damage as long as their is more skag than their is prop its not so bad and dragging it is some what common to a extent. It happens.

 

[metriccrescentwrench]

Re: How important is that fin??

HOW MUCH damage, hypothetically speaking, are we talking about? Honestly, if it's just a bit of damage I'd put a sanding disc on my grinder and reshape the skeg to make it look good and leave it at that. If it's a fair amount, then yes, look at the replacement skegs.

 

[Alumarine]

Re: How important is that fin??

If it's just ground down a bit I wouldn't worry about it.

 

[Shamfarlango]

Re: How important is that fin??

Primarily used to protect the prop as mentioned above. I broke a skeg off and hit one of the unknowns in the water and not only damaged my prop, but bent my prop shaft...so it turned out to be an expensive lesson. Once the drive was repaired, I had a new skeg welded on.
Everything i read said weld a new one and not use a bolt on replacement if you can avoid it. Any weld shop can repair it and it cost me $100. It looks like brand new too!

 

[Jlawsen]

Re: How important is that fin??

Some of you will think I'm nuts but I don't really care because I know the correct answer and believe it or not it's a good thing that you don't.

I've had a lower skeg on a go fast motor let go on me at 80mph. I ended up in the hospital and the boat was never recovered. Now you might argue that this is not a go fast boat but I will argue back that a hard left turn at 35 mph will throw passengers out and can cause the boat to flip.

They are just cast aluminum and the quailty to begin with is poor. If you've drug it and bounced it up a ramp or smacked it into a rock it needs to be checked thouroughly.

The bolt on replacement skegs are probably the better option for repair since they bolt through in an area that usually doesn't get damaged. Only an inexeperienced boat shop would offer to weld a new one on for you. Do not go that route. If you're in doubt, replace the entire casing. It can be a lot less expensive and will give you back piece of mind after you've read this post.

 

[Shamfarlango]

Re: How important is that fin??

I would disagree entirely on the statement that a welded skeg is a sign of an inexperienced shop. It's very common practice. They are designed to break.
I'm not looking to start any major debate, it's just like everything that isn't black and white, lots of opinions. So I will just leave it as everyone is entitled to their opinion.

Absolutely in agreement about inspection of them regularly as part of your maintenance program.

 

[roscoe]

Re: How important is that fin??

Some of you will think I'm nuts but I don't really care because I know the correct answer and believe it or not it's a good thing that you don't.

I've had a lower skeg on a go fast motor let go on me at 80mph. I ended up in the hospital and the boat was never recovered. Now you might argue that this is not a go fast boat but I will argue back that a hard left turn at 35 mph will throw passengers out and can cause the boat to flip.

They are just cast aluminum and the quailty to begin with is poor. If you've drug it and bounced it up a ramp or smacked it into a rock it needs to be checked thouroughly.

The bolt on replacement skegs are probably the better option for repair since they bolt through in an area that usually doesn't get damaged. Only an inexeperienced boat shop would offer to weld a new one on for you. Do not go that route. If you're in doubt, replace the entire casing. It can be a lot less expensive and will give you back piece of mind after you've read this post.

Well, I don't think you are nuts, but I doubt your conclusions.

Skegs don't just fall off from going 80 mph. There are thousands of boats out there that go faster than that, and the skegs are still intact.

The skeg is a prop protector.
It is not a rudder.
If the skeg is not there, it will not cause the boat to veer or turn.

Most importantly, if the boat was never recovered, how can you make the assumption that the skeg broke off, and that it caused the accident?

The boat won't turn if the motor doesn't turn.

If the accident happened as you say, I would guess the steering failed.

 

[boatasticaldave]

Re: How important is that fin??

Thanks all for the great advice!! I don't think it's damaged that bad but I am happy to now know its purpose as it will help me to evaluate possible repair or replace. I also didn't know you could even replace them, so it's great to know as I was pricing lower units to much dispair. Today was my sea trial day, not a very good one as it ran bad and I was quite embarrassed at the slip. Oh well, there is always tomorrow. Thanks again everyone!!

 

[oops!]

Re: How important is that fin??

post pics buddy.....lets have a look !

 

[boatasticaldave]

Re: How important is that fin??

 

[Shamfarlango]

Re: How important is that fin??

View attachment 148779

Thats not terrible and could be easily repaired (welded or bolted on).
I wish i had taken a photo of mine before I put it in the water...you would never know it was ever broken.

 

[spdracr39]

Re: How important is that fin??

Thats not even bad enough to worry about.

 

[Bob_VT]

Re: How important is that fin??

Consider this.

A Skeg repair is cheaper then a good prop. Your skeg leaves your prop exposed to damage.

 

[mommicked]

Re: How important is that fin??

How ironic is it that you damaged your skeg after asking a hypothetical question about what to do if you actually did it ? you should have knocked on some wood!

 

[MH Hawker]

Re: How important is that fin??

Well all I can say I you have joined a club with a lot of members

 

[Frank Acampora]

Re: How important is that fin??

Well, how important is it? It will give the ramp watchers a good laugh. But, on a pleasure cruiser it won't make much difference.

It is true that skeg design is important on go-fast boats and engines as Lawsen said. In fact, Merc. and OMC were at one time touting their skeg design as best for high speed maneurverability. Marketing hype? who knows.

 

[metriccrescentwrench]

Re: How important is that fin??

I notice from the photo you posted that you're missing the gearcase trim tab. It's supposed to mount above the prop on that circular area. While not essential, without it I bet you're boat is hard to turn to port when underway.

And yes, enough of the skeg is gone that it would be a good idea to repair it.

 

[boatasticaldave]

Re: How important is that fin??

Yes i should have knocked on wood, And i'm glad i've joined the club of skeg crushers lol! I will look for replacement. Gearcase Trim tab?!? I guess that explains those holes with nothing in them.... still a rookie to this thing, suppose i should get one of those as well. Wonder what else i don't know i'm missing!! Went back to the same slip today for sea trials #2, tide was out, guess what i found... my broken skeg piece. Odd. Maybe i can make a necklace out of it