Depth needed to safely launch/retrieve Catalina 18 Wing Keel

[majorkong1]

I recently purchased a Catalina Capri 18 wing keel. When I went to launch at my local ramp, even with the trailer tongue fully extended it seemed pretty far from getting deep enough to float off the trailer. My tongue retracted is 56 inches, extended 80 inches (so extending the tongue adds 2 feet). I measured various points against the hull to estimate how deep the water should be to float it off the trailer, but I’m not sure which measurement is the right one to use. Against the hull immediately by the keel is 35 inches high. Where the hull begins to curve up to the side is 40 inches. Above the lower stripe on the side is 46 inches.

I took some measurements this morning and to reach a depth of 50 inches I need to be able to reach 423 inches past the ramp waterline. With the tongue fully extended and vehicle backed just before water reaches the exhaust, it’s 165 inches. So that’s an additional 258 inches (21.5 feet) that I’d need to extend enough so the boat will float.

Does that sound right? If so it seems my only option would be launching with a tow strap. On that subject, can the tow strap connect to the tongue fully extended or does it have to connect further back? Presumably I’d need to add a tongue wheel rather than relying on the jack wheel right?

 

[Timm R Oday25]

Off the top of my head I'm going to say pretty close to the 46" . As you already found out the angle of the ramp wasn't enough to lift the back of the boat off . Is there a differant ramp you might be able to use ?
Making a longer extension isn't that difficult . Pictures of the trailer /extension would help

 

[majorkong1]

Thank you. Below are some photos of the trailer and extension.

This is the only place where I could keep the boat rigged near a ramp on this lake. It’s 10 min away from my house. Other options are to dry sail it at a different lake (45 min - 1 hr 20 min away) or store it elsewhere so I can launch from a different ramp. But then I’d have to step the mast and rig each time that I sail, which I’m trying to avoid.

Off the top of my head I'm going to say pretty close to the 46" . As you already found out the angle of the ramp wasn't enough to lift the back of the boat off . Is there a differant ramp you might be able to use ?
Making a longer extension isn't that difficult . Pictures of the trailer /extension would help

tongue retracted

Tongue extended fully

 

[Tedd]

There's a recent thread by someone with a similar boat trying to work out the same thing. You might find valuable information there.

You should measure the height of the waterline at about a foot in front of the trailer's axle plane. See the sketch below, which is from when I extended the tongue on my trailer. (I'm not sure why the wheels don't show up in the first image.) The boat should float off the trailer at about the point where the water reaches the waterline about a foot in front of the axle, plus or minus a bit depending on hull shape. I think I assumed that my boat would need the water about an inch above the waterline at that point, which seems to have worked well.

On my boat, the paint stripe is quite a bit above the actual waterline, at least at the load I normally launch with. If you can see where the actual waterline is on your hull it'll make the measurements more accurate.

Every extra inch of depth you need means putting the trailer about six inches further into the water. (Plus or minus a bit, depending on the slope of the ramp.)

 

[majorkong1]

Thank you, this is super helpful.

So my measurements were relative to the bow of the boat, not 1 foot in front of the axle. I didn’t measure that exactly but I’d estimate that point is around half the boat length, so 9 feet. That means I would need to add 12.5 feet to my current extension instead of the 21.5 I calculated earlier.

There's a recent thread by someone with a similar boat trying to work out the same thing. You might find valuable information there.

You should measure the height of the waterline at about a foot in front of the trailer's axle plane. See the sketch below, which is from when I extended the tongue on my trailer. (I'm not sure why the wheels don't show up in the first image.) The boat should float off the trailer at about the point where the water reaches the waterline about a foot in front of the axle, plus or minus a bit depending on hull shape. I think I assumed that my boat would need the water about an inch above the waterline at that point, which seems to have worked well.

On my boat, the paint stripe is quite a bit above the actual waterline, at least at the load I normally launch with. If you can see where the actual waterline is on your hull it'll make the measurements more accurate.

Every extra inch of depth you need means putting the trailer about six inches further into the water. (Plus or minus a bit, depending on the slope of the ramp.)

 

[SteveHughessails]

I was at a store today, I came out and the truck beside me had a hitch extension. I thought to myself it would be simple to make an extension to use once you get to the boat launch, remove it for on road/highway towing. I took a picture but it was out of focus. I found this one online. Super simple. I would go telescopic myself to slide it back in the truck when you're done. No modifying the trailer etc.

 

[LloydB]

A hitch extension wouldn't work on my pickup I think because the rear gas tank or the spare tire would get in the way. I have however been considering putting a long extension that could be added to the trailer for those really shallow ramps that I rarely visit or a shoreline launch we're no ramp exists. I've got a buddy that launches his drift boat off a cliff with a rope but recovers it downstream at a real ramp where he does not have to concern himself with sinking in the muck to the axles.

 

[SteveHughessails]

The extension would fit in the hitch like any regular receiver. It wouldn’t slide through/under the back of the truck. It would simply stick out.
I don’t need an extension to launch either of my boats but I just noticed I do have the ability to extend both of my trailers like the OP’s. Good to know

 

[Rick Webb]

Hitch extenders are readily available at like a two-foot length. Inexpensive and may be just enough. Look at Harbor Freight.

Another thing I found helpful is to use the draw bar with the longest drop you can find (that doesn't rub on the ground) when launching. I carry two and switch out at the ramp between one I tow with and one I launch with.

 

[JBP-PA]

From the first picture that does look like a pretty shallow ramp and maybe your only option is a strap. I would think on an 18ft, the trailer jack wheel would suffice. The problem you might encounter is that the ramp is too short to use a strap.

 

[majorkong1]

I did check that and the ramp is long enough. Out of curiosity why don’t think the jack wheel would work with an 18 foot boat? Is it related to the tongue weight?

From the first picture that does look like a pretty shallow ramp and maybe your only option is a strap. I would think on an 18ft, the trailer jack wheel would suffice. The problem you might encounter is that the ramp is too short to use a strap.