Increase Transom Height? Your opinions please.

I recently purchased a 16' Starcraft utility. Very good condition. Solid.

However, this boat has a 15 / 16 inch transom height. Had the transom been made such that it's top was at the same height as the gunwales, it would have been a 20 inch transom.

I intend on putting a new outboard on this boat, 20 - 25 hp. And this outboard may be used on other boats in the future. My sense is that I'd rather purchase a long shaft outboard. Also, I'd prefer the "security" of having a taller transom on this boat as it will be used in bay also, not just on small lakes.

So I'm thinking of increasing the transom height to 20". I'm thinking I'd do this using a sandwich of 1/4" aluminum and epoxy encapsulated marine ply through bolted on to the existing transom with some additional internal bracing as well.

What are your thoughts on this idea? Do you think that the benefits are worth the cost and time required to do this work?

I would buy a mini jack plate or something like that. I wouldn't tear the transom up trying to make the entire transom 20". I'd purchase a different boat before doing that.

This is what I did in a similar situation.

ericman said:

This is what I did in a similar situation.

Click to expand...

Looks good. That's what I had in mind. May even be easier on my boat.

How did it work out?

I'd definitely recommend a jack plate. They can be had cheap enough or one could be made to your own specs fairly easily and at about the same cost. I just wouldn't want to be making such a permanent modification to a boat that might find a new home at some point. That, and I trust the manufacturer's design and engineering much more than my own even though I think I do pretty good work. Just my thoughts

kstrayhorn said:

I'd definitely recommend a jack plate. They can be had cheap enough or one could be made to your own specs fairly easily and at about the same cost. I just wouldn't want to be making such a permanent modification to a boat that might find a new home at some point. That, and I trust the manufacturer's design and engineering much more than my own even though I think I do pretty good work. Just my thoughts

Click to expand...

Jack plate won't cut it as one of my goals is to raise transom so boat can be used more safely in rougher waters. These boats are made from the factory with either a 15 in or a 20 in transom. All aspects of the rest of the boat are identical. Indeed the transom starts off at 20 inches and is then "cut out" to get down to 15 or 16 inches. With this boat the cut out does not run the whole width of the transom, only the center portion, so it will be ease to do a structurally sound increase in height. The job shown in photos above is an example of a structurally sound modification. And if you are smart about it, you can make the mods so that they are reversible. Just gonna cost some money for the heavy duty aluminum plate and perhaps some TIG welding.

Replace the transom wood with a new one the desired height and have the a piece of aluminum the same thickness as the transom skin tig welded in.
It's been done before.

I have a Lowe 1448 that was made for a short shaft motor with a 15" transom. It came with a Merc short shaft that I traded for a newer Yamaha 40/30 jet. I rebuilt the whole transom similar to the other guys transom however mine is now 20" instead of the original 15". Added bracing to the corners, two heavier knees for added strength, and got rid of the wood core by making a honeycomb of aluminum between the exterior .100 sheet. It's a bit heavier but a whole lot stronger and higher than the gunnels by about 4 inches. It's a perfect fit for the jet and now will accomodate a long shaft prop unit instead of the locally rarer used short shaft. Of course I now have more money into the boat than I'd get out of an old rivited hull but I bought it right to begin with and I have confidence that it's strong enough to handle the extra HP that the jet puts out. it's only 5 HP over original top rating and it's way stronger than original now.