Converting 20 inch transom to 25

Hi all,

I am ready to bond my ply to existing transom skin but want to make sure my measurements are correct beforehand.

I have a 5.3m Yalta Craft Odessa in Australia which i believe originally was a 20 inch transom.

So when measuring for the my new transom marine ply i simply added 5 inches to the existing skin. Is this the correct way to go? If i measure from bottom of hull to the new cutout the measurement is 660mm / 26 inches. But this measurement is at an angle.

 

Update - i put a spirit level at the bottom of the hull, measures 24.8 inches straight up to new top of ply.
I will also be installing a hydraulic jacking plate so not sure if it would even matter too much with this on there?

 

Transom height is measured at the angle. Just measure the outboard from transom bracket to make sure the anti-ventilation plate is at keel level with your new transom. I have never fitted a jack plate but imagine they would allow some adjustment with positioning.

 

Yup. Plus 5”.

Jackplates are mounted in the typical ob holes. The extension of plus 5” will need to be well tabbed to the old hull.

 

It looks to be a complete transom replacement FG.

 

Thanks all