When two boats share the same hull type — in this case both the ThunderJet Alexis OB Offshore - 21 ft. 2008 and the ThunderJet Alexis Outboard - 20 ft. 2008 are modified vee designs with aluminum construction — the buying decision usually comes down to a handful of practical questions: how many people are you putting on the water, how far do you trailer, and what does your tow vehicle weigh?
The ThunderJet Alexis OB Offshore - 21 ft. 2008 carries a rated maximum of 500 hp. Engine data for the ThunderJet Alexis Outboard - 20 ft. 2008 wasn't available in our records — check the manufacturer's spec sheet before sizing a motor.Both carry nearly identical fuel loads — 5 gal and 5 gal — so range won't be a tiebreaker here.
Both boats are rated for 6 passengers — a good fit for a family of four or five plus guests. Comfort at capacity is another matter; the longer hull typically means more seat options and better weight distribution.
Bottom line: The ThunderJet Alexis OB Offshore - 21 ft. 2008 at 21,0 ft is the right call if deck space, comfort, and entertaining are top of your list. The ThunderJet Alexis Outboard - 20 ft. 2008 at 2,0 ft wins on trailering ease, likely lower purchase price, and simpler docking — a solid choice for a buyer who wants more boat for less money.