Jack plate or not?

[ReelThyme]

Could someone tell me the DISadvantages of adding a jackplate to a boat, and why?
I have a Cobia 211 bay/200 Yam with the motor bolted to the transom and was wondering if a jack-plate preferably Bob's would actually improve performance or could actually hurt the overall performance.
I always believed it could only help even if ever so slightly
thank you in advance..

[Reelnative]

You get less bite in the water with a jack-plate and it will hurt your overall top end speed. It is used correctly on a tunnel hull application where the water colum is brought up to the raised motor height.

[ReelWork]

Wrong and Wrong... It can improve your top end by as much as 5 mph and your hole shot and normal running is better because the water running over the lower unit is a little cleaner and higher. By higher I mean that the water exits the keel at the transom at an angle about 45 degrees or so. With a plate, you actually dig the prop lower in the water like in rough conditions. Then when it's flat out, you can raise the plate bringing the lower unit and therefore DRAG out of the water and scoot right along...

Does your Cobia have a tunnel?

[SeaJay]

If adding a jack plate increases hole shot and also increases top end by 5MPH, then it sounds like the magic bullet that will transform every boat into a superior performer. If this is the case why don't all boats sport a jack plate?

[ReelWork]

by AS MUCH AS 5 MPH... Mine increased about 2 MPH with a 125 Merc....

and yes, it is the magic bullet for boats that can benefit by having one on. Since I obviously need to clarify on that statement as well, a tunnel hull can run up to 6-10 inches shallower with one sitting on the back and not having the lower unit skeg dragging as low..

My boat is substantially different in the hole shot and shallow running when compared to when it didn't have it. Before, I could run in about 20inches - now, I can run in about 14 inches. the shallowest I have run was 9 inches, but I need at least 18 inches to get out of the hole compared to about 30 inches before. This is because I can now tuck the motor up and in, bringing the stern up and cavitating the prop once I literally jump on plane. As I do, I have to almost immediately start lowering the plate to keep the prop in the best water. I can run my boat with the plate all the way, but it's cavitating the prop quite a bit and not necessary once I am up. Additionally, in the shallows, I can raise the plate and with just a little tilt, the lower unit is clear of the hull when drifting....

If used properly, they can't be beat!

[tseel]

Reelwork has pretty ably described it, but let's make it simpler. (1) The plate enables you to take off from shallower water than a boat without it (2) it lets you run higher with your motor, and (3) with the prop in enough water, more speed, less drag, more efficient operation. Bob's is the best, although I have a CMC. Plates are pretty much standard equipment for Texas bay fisherman.

[Canazes9]

Agree w/ reelwork & tseel,

Bob's is the best. Most cases a properly installed and used jackplate will add both holeshot and top speed. With boats that are bow heavy, and need all positive trim to hit max speed ( and feel like they could use more and/or a better biting prop) a jackplate has the effect of shifting the center of gravity in the boat further back, thereby giving the outboard better mechanical leverage, more ability to hold the bow up and greatly improved top end - that's where the "as much as 5 mph" comes from (on rare occaisons could be even more).

A jackplate could hurt you if you've got one of those very bow light boats that porpoises at mid-range speeds. Shifting the center of gravity further back is just going to make the porpoising worse! Normally boats like that are cured with a planing aid, and jackplates will provide all the holeshot, shallow water capabilities, but won't improve the top end.

Why don't all boats come with them? They're typically an additional $600-$1,000.00 installed, and they provide the capability of raising the motor so high it starves for cooling water and burns up. Then the dealer has to deal with this uneducated boater screaming that it's the dealers fault, repair/replace under warranty.

I have a Bob's on my boat, 6" vertical travel, 7.5" total lift, adjustments as little as 1/8" are easy, the hydraullic unit is installed inside the boat, out of the elements, and the abuses of salt water (not that the unit probably couldn't take it, just a little extra peice of mind). I believe Bob's also has the longest standard warranty.

[maschweikert]

you will see many bass boats with them on them. almost all of the guys down here in fl that I know use bobs. it is usually the first thing they put on. one of the boats I run has a bobs plate on it, and a low water pickup. but this is not for all boats, the hull is a tunnel hull and will run in about 4in. of water. the plate really only has one downside, price. I might add that a 4blade prop will help you as well, if you are more of a shallow water fisherman. I might add, that when I get on plane in shallow water, I jack it up all the way, hammer it down, raising the rpms, and then slowly lower the plate and I am on plane in no time.

[Fishfull Thinkn]

One disadvantage that I didn't see mentinoned is leverage. Some boat transoms aren't designed to handle the motor hanging off 6 to 10" off the transom and creating lots of leverage. Both my boats have jackplates and in both cases they have been wonderful. Both top end, holeshot and shallow water cruising has been improved. HOWEVER, not all boat manufactures will stand behind the hull warranty when a jackplate is used. Our 2000 Lund is a perfect example. The warranty specifically states that transom damage due to the addition of a jackplate will void your warranty. I called Wellcraft directly because it doesn't state anything in their warranty and they said that adding a jackplate is not a issue and wouldn't void the warranty.
Check with your manufacture to be safe.
Good luck
Todd