I just purchased a 1973 Catalina 22 with an illegal marine head. It appears to be in good condition but, of course, it pipes directly to a through-hull under the v-berth. My question - Does it make sense to keep the marine head and add a proper holding tank or take it out in favor of a portable and leave the through-hull alone? I'm not planning a lot of overnights on board but taking out the marine head sounds like it would be as much trouble as adding a holding tank.