Good used mid size SUV for towing

SUV.....Sports Utility Vehical. Generally derived from 'body on ladder frame' pickups

CUV.....Cross-over Utility Vehical. Generall derived from 'monocoque...unibody' passenger vehicles....or CAR

First gen Highlanders are derived from a Camry. Second gen Highlanders are derived from a mini van...Sienna. So are CUV's

Pilots are derived from a mini van, Odyessy. So are CUV's

RAV4...a Corolla . So a CUV

CRV....a Civic. so a CUV

4Runner is a SUV

Xterra is a SUV

In Calif, trailer brakes are required on any trailer 1,500 lbs or higher. Personally, would not tow anything over 1,000 without trailer brakes...just not safe enough for me

my 2011 Highlander with the towing package is rated for 5,000 lbs. without the towing package, 2,000 lbs. As was the Pilot for a boat, for a TT it was 3,500 lbs.
bumpy

You're the fella whose wife has the Highlander, right?

I think it likely that all the suggestions so far will have the same must-have-brakes-on-trailer requirement for loads over a thousand pounds as the Highlander does.

On that subject:

Adding electric brakes to a trailer is really no big deal- parts can be had for a hundred bucks a wheel or so. With that mod and a brake controller, your wife's car can pull the boat.

On edit:

If you go this route, do make sure to get corrosion-resistant parts since they'd obviously be exposed to more water than on a regular trailer. Read more about boat trailer brakes at this link

Toyota Highlander or Honda Pilot are rated at 5000lbs max towing and should handle that boat with no problem. My Sienna has the same engine as the Highlander and pulled a 6x12 enclosed trailer (over 3000lbs loaded) just fine.

You might check out an Xterra. The '05 and newer had plenty of power with the 3.5L V6 and they have a good stout frame and actual 4wd.

Toyota 4Runner?

Most mid sized SUVs with V6 or V8 have 3500+ pounds of tow rating which is fine for your needs. Pick your favorite. Even a compact CUV would work, like Ford Escape V6 from that era.

I tow with an 08 trailblazer with a 6.0 v8. it has helper bags on the rear and plenty of power and torque to hardly flinch at my 19 footer. i've towed much heaver than my current rig with it, and have never had any issues. the trailblazer with the i6 is a pretty stout vehicle, and a good place to start looking in my opinion. get a trans cooler and you'll be set