I would have agreed with you a few months ago but recently on my last two visits the food was poor. Chips cooked in old fat, stewed veg and dirty tables. Shame! it used to be my regular when in Gosport.
You certainly get quantity if not always quality! The food reminds me of school dinners - everything comes swimming in gravy. Good for a "blow out" after a hard day on the water but not for a romantic meal for two!
Also worth trying the Clarence down the road. Very much a locals pub. Food is similar to the Castle but has a micro brewery and serves an excellent pint.
