Hi and welcome aboard , so you joined a sailing club ehh . Why dont you rent out a few boats from them , ask around and see who needs crew , throw up an add at the club billboard and get you and your son out on as many boats as you can before you make the comitment to buying one . Unless you can afford to change boats at the drop of a hat and money is no object .Your taste in boats may change drastically once you get going .
Yes you and your son could crew a large cat if you know what your doing , even so , I think youll find that 2 is a very small crew on a boat of some size . Not that it cant be done , but its going to be work . Hard work and sleepless nights if you plan on offshore sailing .
Offshore minimum size is dependant on the crews experience , not the boat .
If you dont know what your doing , a bigger boat is not going to help you , in fact it may hurt you .
Its great that your getting into the sailing life with your family . I hope your son is enthused about it ,13 yrs old , wow . I wish my dad had plans to buy us a 45-50 ft Cat when I was 13 well , not a Cat , I prefer the monohulls .
Theres a bunch of Aussies on the net here and Im sure theyll chime in with recommendations on a small boat to get you going .
Its hard trying to nap with that bilge pump alarm going off all the time