I also installed the Atlantic Towers arch and agree with Pat about the 45 degree post. Mark's set up on Cream Puff is also strong. We've sailed about 3000 blue water miles and not experienced any sway. We do not carry the dinghy on the davits while on passage. We are also adding a "shock" halyard that goes to the top of the mizzen mast and splits to both sides of the arch. I used this arrangement on my last boat and found it comforting when bashing into head seas.