Here's what I did when I owned my 265 Express. Worked really good:
1. On your swim step, remove two existing SS bolts holding the swim platform to the SS tube bracing under the swim platform - ie. two that are 18" or 24" apart and in the center of the swim platform if possible.
2. In their place, install two SS eye bolts with washers and bolts under the SS tubing for strength.
3. Take a plastic milk crate and place it vertically between the two eye bolts
4. With e pair of long and strong nylon straps, strap the top handle of the Honda to one of the eye bolts (left) and another to the right eye bolt.
5. Plug your battery charger (nearby) into the Generator. Might need an extension cord and might need to install a 3 prong plug on the 110V wire to your battery charger.
With the above, the generator will be above any wave activity and in a lock down safe mount. Any gas exhaust will, of course, blow down wind and away from your boat when on a sea anchor. When not in use, the empty milk crate (no mainentance since plastic) can hold "stuff" in the cabin somewhere.
Good luck!