Boy, thats a tough one. My first reaction is to say: Buy something now for the lakes, and then buy something later for the ocean. Another issue: Buy two singles, or a double?
If two singles, the Wilderness Systems Tsunami ($1,100 for the 140 model; wildernesssystems.com) is a decent light touring boat that would be great on lakes and would work well in ocean conditions provided conditions are not unreasonable. And it has lots of room for gear. So you could buy that now, have a great time on lakes, then take it with you to Hawaii.
The thing is, I should think that in your climate theres a lot to be said for a sit-on-top kayak. Wilderness Systems makes one called the Tarpon 160 ($1,100) that has enough room for camping gear. The Tarpon is a great boat for lake paddling in warm weather, and its easy to manage around the shore. So it would be a great boat for enjoying the water and learning to paddle. It even would be okay for calm ocean water in Hawaii, where, after all, it is warm as well.
If you want one boat for the two of you, then analogous choices would be a Wilderness Systems Northstar ($2,200), an excellent touring boat for two. In a sit-on-top, the Tarpon 130T from the same company ($800) can handle two. Packing may be a little tricky, though, as it offers only two deck wells with no hatch-covered storage. So you'd have to pack frugally, and store stuff in watertight bags.
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