Just Buy It
Tell the wife you painted it red just for her tell her its got nice sleeping arrangements and once she lets you buy it, fill the fuel tank up and tell her you are going fishing. Tell her it is only a day trip, give her a big hug and kiss and tell her you will see her later tonight. Then later that night call her and tell her you had motor problems and the sat phone battery is dying but not to worry you will be ok and will call her when you get a chance. Also call the coast guard and local police and tell them if your wife calls and wants to report you missing to just take the info down and tell her they will call her back when they hear something. Then just go fishing for a week or 2. Come back with the fish hold full and a big smile on your face hey she can only yell at you for so long and many of us can let it go in one ear and out the other. Hell she may even do you a favor and pack her own bags and leave.