you got a few ways to go..
1 - and best - Stour estuary , the best road is from Mamingtree /Mistley to Harwich, semi following the river, really great 7 mile twisty burn, do it a few times and get it right and get quicker...look out for the lorries on the way to boat.....and tractors, goes for all roads in the land of the tractor boys !
2 - Aldeburgh, Southwold, Thorpenss - nice fast burn up A12 towards Norwich, thrugh Glemham and the Hall, and then turn right and on to the coast, nice to go to coast and decent beach, also Waldringfield
3 - Hadleigh , Sudbury - not great
4 - Bury St Edmunds - average
5 - dont bother with Norfolk, i went all the way to Cromer - and wished i hadnt bothered !
have fun! check out the Orwell, go to Woolverstone / Pin Mill under the bridge , also the other side, towards Felixstowe, turn off for Levington and go to marina, nice nature reserve walk by river there
Woodbridge is ok - river walk to Kyson point, then carry on to Bawdsey..should keep you busy