Inflatables

There are many kinds of inflatables that a cartop angler can use but what would be of interest are the ones with a hard transom capable of mounting an outboard. These are constructed of various materials but it's best to invest in one made of Hypalon. This material is superior in U.V. and puncture resistance and lasts a very long time. Though, a bit expensive. Cheaper models come in vinyl.

A 11 foot model is just about what a solo angler can handle. Anything bigger would require two people or a roofrack winch to load.

These boats can handle a lot of load and are virtually unsinkable. They are stable casting platforms and can actually take you quite a ways offshore. Most of them have an inflatable keel that allows the boat to take on waves and track decently. Rigid bottomed versions would be better on all counts but i haven't had the opportunity to put one on my roof. as with any inflatable, it's better to pump them up offsite when convenient. Keep all your gear in a milk crate and stuff you don't want wet in a dry bag.
As with any inflatable, be mindful of sharp objects in the boat.