My sailing experience is primarily on monohulls from 21 to 41ft in length throughout the Caribbean, and Long Island Sound. I was wanting to see if the Hobie 18 was to large to sail single handed if capsized?
In my humble opinion the H18 is actually an easier boat to solo than the H16 once you're on the water (easier to tack, easier to manage the jib, better handling in choppy water, more tuning/de-tuning options). It's also less prone to capsize due to the dreaded pitch pole.
But don't mistake the H18 for a Tiger simply because they're both 18 foot cats. The Tiger is no starter boat (experienced sailor or not) nor is it a boat you want to plow up on the beach a dozen times every weekend. The Tiger is a high performance two-man race boat that will make you pay for your mistakes in a hurry. You're much better off going with the H16 or, if you will have mast up storage, finding a used H18. I love my H18 and sail it solo most of the time but I wouldn't want to have to rig it by myself every weekend if I didn't have mast-up storage.