From the looks of the picture, you're going the wrong way. The collapse is on the left side of the filter and the pressure should be on the right side? Unless you had the wrench in a funky way. Just like your other boat it should be very easy to get off. Now it maybe very tight so you may have to apply a little more pressure to get it loose.
You should be pushing the wrench toward the rear of the boat.
Hope this helps.