The move had been lined-up before Michael Appleton’s arrival as head coach last week.
Hughes had been recommended to the Tangerines following his Fratton Park departure at the end of the season.
The 18-year-old now goes straight in their development squad, where he’ll be granted the time and patience to flourish.
The week-long stay saw the youngster from Lyndhurst, New Forest, spend a week with the Seagulls’ under-23s, yet no move materialised.
Now Blackpool have acted upon the recommendation of senior scout Neil Sillett, who previously worked at Fratton Park as a long-time physio and later in the role of head of Academy recruitment.
Hughes made his Pompey debut in November, starting at left-back in a 3-0 success over Crystal Palace Under-21s in the Papa John’s Trophy.
He would also be named on the bench four times, including League One fixtures at Wycombe and at home to Sheffield Wednesday, yet wasn’t utilised.
Hughes featured in Pompey reserves’ progress to the quarter-finals of the Hampshire Senior Cup, before a 4-0 defeat at Farnborough in February.
He joined the Rocks on loan in December, operating either at left-back or a left-sided centre-half, as he rattled up 14 outings.
However, at the end of his two-year scholarship with Pompey’s Academy, he was released at the season’s end along with Izzy Kaba, Conor Manderson, and David Setters.
In contrast, fellow graduates Alfie Bridgman and Dan Gifford, also Bognor loanees, were given third-year scholarships, while Harry Jewitt-White was handed first-year professional terms.
Blackpool finished 16th in the Championship last season, their first back at that level after returning through the 2021 League One play-off final.
They lost highly-regarded boss Neil Critchley three weeks ago, after agreeing to become Steven Gerrard’s new assistant at Aston Villa.
No doubt Pompey fans will watch Hughes’ progress with interest with their own Academy having stalled in recent years.
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