1999 Ventura 20 Trailer Set Up Dimensions

[rsk07001]

Hi. [I am] new to the forum here but been reading it for a while now. Great place and led me to buying a Boston Whaler boat of my own after having many in my family.

I just purchased a 1999 Whaler Ventura 20 with a Mercury 200 EFI. Unfortunately I had to travel last minute for business this week and am in need of the transom-to-bow eye measurement in order to ensure that the trailer I will buy will work for the boat. I was wondering if someone on here had that measurement; I have been searching all over the place for it. I appreciate the help and look forward to being on the forum.---Bob

[jimh]

The length-over-all of the 1999 VENTURA 20 is 19-feet 8-inch or 19.66-feet. I located a photograph of the hull in the 1999 catalogue. I measured the length of the hull in a photograph to be 10.25-inches. Then I measured the length of the distance from the bow to the bow-eye in the photograph to be 0.75-inch. Then I set up a relationship:

10.25-inch/19.66-feet = 0.75-inch/X-feet

I solved this relationship for X, the distance from bow to bow-eye:

X = 0.75-inch ×19.66-feet / 10.25-inch

X = 1.43-feet

Now I subtract that distance from the length-over-all to get the distance from transom to bow-eye:

19.66 - 1.43 = 18.23 or 18-feet 2.75-inches

That ought to get you quite close to the actual dimension. If the trailer you will buy is so short that it cannot fit the boat if that dimension is more than a six-inches off the actual, you are buying a trailer that is too small.

[Binkster]

Although I studied algebra in high school many years ago, this is the first time I have ever seen it used to solve a problem in real life. I never realized it could be helpful. Are you sure the photo was at 90 degrees from the photographer? Also photos don't always show true measurements, Using a line drawing would be better.
It doesn't matter anyway, the bow stop is adjustable on the tongue of the trailer. The important thing is to have the tongue weight right, and the transom not hanging over the rear of the trailer. Most good trailer builders have the specs from every boat builder for every model.

rich

[jimh]

Rich--the angle in the photograph really does not need to be precisely orthogonal to the keel centerline. All the distances are seen in at the same angle, so if the boat appears to be 10.25-inches long in the image, we can scale from that other dimensions that are in the same line. Since the transom-to-bow and transom-to-bow-eye distances are exactly on the same line, there is no concern about the angle at which the boat is photographed. We know one distance measurement from the specifications, and then we scale the photo-image to that scale, and interpret the distance. I don't think we need the NSA or CIA photographic-interpretation scientists, but, if any are reading, maybe they will chime in, or should I say chine in.

[rsk07001]

Thanks for the very helpful replies. That is the most algebra I have seen since grade school. After looking at the later 21-foot Ventura models and figuring the bow eye didn't vary too much from year to year, I chose a Karavan 4,100-lbs capacity, [unclear but perhaps meant double] bunk, single-axle [trailer] with bow roller. It appears Boston Whaler measured the boat of 19-feet 8-inches to the edge of the anchor roller. That gave another 4 to 6-inches and 18-inches back from the bow eye. Deducting 2-inches put [the distance between the bow eye and the transom] at 17-feet 8-inches, all said and done, so Jim's Algebra was dead on. The trailer was bought last week; I avoided the three-week lead time. Trailer came in yesterday and fits really well. Just a few minor adjustments to the bow roller and that is it. Looks like a great trailer for the money that has some serious tow capacity for a single axle. Thanks guys.

-Bob