---

Is the main purpose of a jack plate to allow easy adjustment of the height of the engine or are there other benefits too? Do they put more strain on the transom?

---

Generally, the jackplate was designed to enhance high-speed performance in smooth water. The less lower unit you have in the water, less drag, more speed, etc (given that you have a performance prop that can run shallow and low-water pickup tubes on your lower unit).

As you stated - it is great to be able to adjust your engine height easily to find an optimum level for your type of boating. You can even adjust some hydraulic plates while on the run - meaning you can really optimize the engine height based on sea state (i.e. you can bury the lower unit deeper to get more prop "bite" in heavy seas).

The other advantage of a jackplate is that many have some degree of setback.

For a great article on setback brackets (used more prolifically in saltwater and bigwater applications vs the jackplate (height adjustment) found on inland lake applications), see:
ARTICLE

What I love about my jack plates, is that they give me a combination of the above (height adjustment and 10 inches of setback).

Dave

---

Derwd,

No more stress on the transom if you are thinking of a short set back, 4-5 inches? I would not be concerned provided your transom is good today. Longer than that I have a professional take a good look. I have used these in the past on other boats with good results and will be adding on my BW next season.

Good luck B)

---

Mine allowed me to adjust the engine height a little higher and more rearward to catch the less turbulent water coming off of the bottom of the transom...better feed to push more weight while maintaining speed while also maintaining the proper rpm's. While someone else is driving, go back to the transom, hang your head over the back and look at the water coming off of the bottom of the transom and how it is feeding the lower unit. Some theories are that there is much less turbulent water 5-6 inches back, your prop will get a better bite, your engine will get better/smoother water feed to the impeller and you can run in fewer inches of water. The water is a little higher a few inches back after coming off of the bottom of the boat. I do not know of any negatives associated with a jackplate other than the initial cost (or usage/hydraulic problems). They are standard issue on many of Texas' tunnel hulls to run higher and farther back. Many run a compression plate in front of the jack plate to distribute the engine load. I am seriously considering one for the back of my '70 Katama due to bolt holt pattern problems. Paul

---

Derwd, Im not sure if its been mentioned but you can also run in more shallow water as less of the motor is in the water. You see these alot on flats boats.

---

Thanks for the link to the article and all the replies, sounds well worth considering. It seems like the only two drawbacks are an increase in static trim towards the stern, and increased transom torque when trailering. (and adding hydraulic steering if not installed already).

---

Also meant to mention that I was surprised to read in the article that Dave referenced how Whaler actually "built up" the transoms on some Outrages in order to facilitate the setback bracket and eliminate the low transom. Am wondering if anyone has seen one of these in person or has one. I like the idea and am wondering if I could replicate it myself?

---

Do you have a the water over the transom concern? I have seen some people close the transom in and add an outboard bracket. I have also seen some people create a fold down door inside to prevent any water from over the transom entering the cockpit. I guess at the end of the day it depends on what your objectives are and how much work/money you are willing to do/spend to realize them.