I ran a girlfriends 14'6" Sillenger (just like the Calipso's tenders in the beginning) out of the Kihei ramp for a couple years (40 Hp Johnson). Even went all the way around Kaho'olawe once (8 hours, no stops). Took it from Mala to Lanai for a couple camping trips. Broke down outside of Hulopoe Bay the second time and luckily got to take the ferry back. Got parts and went back the next day to retrieve it. More than once, had it in following seas so big we would surf uncontrollably into the back of the wave in front, filling the boat with so much water the cooler and gas tank would nearly float out. Coming out of Molokini one day the southerly wrap from strong easterlies nearly flipped us when we crested the first roller. Only time out of Maalaea, the trades coming back from the Pali were so strong we had everything as far forward as possible, including ourselves, and the prop felt like it was the only thing touching the water. Been surrounded by a 14 whale heat pod out by Molokai and was more than a little worried. SeaFire pointed us in the direction of a basking tiger shark once, which we found, and it was as long as the boat! It dove before I could get the camera in the water.
Those were the days, glad I survived! Make sure the weather is calm and flat, be safe have fun.