Mark,

  I agree with the two 60' masts, with three additional notes.

ICW AIR DRAFT

  55' to 60' sounds like a good practical limit because some of the ICW is only 65' at exactly the right tide and wind conditions -- a few of the bridges are closer to 61' to 63' for various reasons, and there's no federal budget or desire to change that. 

SAIL AREA

    - A 48' maxi trailer is probably going to weigh noticeably less than the HP50 cruiser, so two 60' masts are probably overkill.  Though I do like overkill -- you can always reef, but you can't create sail area or air draft that isn't there.

TRAILERING LENGTH

  I personally would have to go with the simpler-is-better approach of skipping telescoping masts, and would want something as close to 56' or 60' as possible.

  However, oversize load limits and trailer clearances might encourage me to consider two-part masts in order to keep the trailer length down to 40' to 50'. 

  Oversize load limits vary from state-to-state; in Maine we can have a total length of 65' and a trailer length of 48' without needing a permit.  I wouldn't mind a permit because I'd normally only be hauling the boat twice per year, in which case I'd want to keep the total size under the limit where an escort vehicle is required, which is under 12' wide and and under 80' for total vehicle+trailer length of 79'. 

  However, practical limits like going over bumps and around corners are probably closer to 10' wide and as short as you can make it.  Two-part masts and fold-up bows on the leeward hull as shown in the original Ex40 renderings would go a long way towards keeping the length manageable.

        https://drivinglaws.aaa.com/tag/trailer-dimensions/
        https://www.heavyhaul.net/oversize_permits-escorts-requirements/
        https://www.heavyhaul.net/maine-permits/

        - Mike

 

If you choose to limit yourself to the ICW, it has a controlling height above the water of 65' except for one bridge between Miami and Ft Lauderdale which is 56'. To see more details just google "icw controlling height".

I have not seen a design mast height for a HP, but my guess is that given a quoted sail area of <1000 sq ft for the HP50, split between two masts on a schooner rig, your mast is going to come out under that anyway. 

A rough back of the envelope calculation for a 500sq ft per simple triangular sail gives a 20' E and 50' P. Given you'd have some roach, the E and/or P will actually be less than that for 500 sq ft. Add 10' for bury and from deck to tack, that gives 2 @ 60' masts.

Mark.