I own a 2010 mazda 3 hatch and I was wondering if I can tow a small fishing boat behind it, and what is the max weight limit to be towed.

 

Note the manual says the vehicle is not rated for towing anything - though I beg to differ for light loads...

https://www.mazda3club.com/mazda3-mazdaspeed3-98/truly-hidden-hitch-53213/

As for weight of what you can tow, here's the numbers for my 2007, GVWR (gross vehicle weight rating) = ~3800, vehicle weight = ~2700 ... difference of about 900# minus the driver weight & 'stuff' in the car for total towing weight should be fine.

I've only got a small trailer (#250) and a dirtbike (#140) which is well below the limits I mentioned above, and have had no issues so far.

Good luck.

 

I agree, as long as the weight isn't considerable (>800 lbs), you should be fine. But if you plan on towing the boat very long distances, get a transmission fluid cooler. They are easy to install and will give you some peace of mind.