I guess I'm lucky in some respects, wife will go anywhere as long as there is sand between her toes. Its does get easier the longer your married and sometimes encourage the girl trips to capitalize on future solo surf trips.
If your wife knows your buds that golf as most avid golfers take trips too without their wife's so use that in your pretext of your desire/necessity for a surf trip. Honey can't do it without ya, play it up, trip together would be wonderful for us but do to limited budget not sure can swing it. If we go together these are our choices and if was able to go solo could stretch it to this level or maybe not a good idea now, show off your puppy dog eyes. Certainly including her speaks volumes from her eyes (he's so wonderful) over dropping a solo trip leaving her out of the equation. So in the meantime keep the dialog going, odds are in your favor most of the time so seek tentative travel plans with your agent for solo as well as both of you. Sometimes just the thought including her can work wonders, better than explaining why you want to go without her and lessens the pay back when you return. Their's always mileage for letting you go solo even when she agrees but the drive can be less bumpy.