Traveling 'outside' along the east coast involves 'inlets', many (less than Class A inlets - used by 'ships') with sandbars at where the inlet's current meets the ocean.
Traversing inlets with the 'wrong' wind and current, these inlets can sometimes be 'very difficult'. These minor and 'less than Class A' inlets are also 'shifty', the USCG constantly changing the channel markers as the bottom contours of the 'channel' shifts about and changes - the reason that most charts and chart plotters will have the markers 'absent'. It takes quite a bit of practice and expertise to 'shoot' an inlet during 'the wrong' times .... you'll get better at it, the more inlets you use.
So, unless you have 'local knowledge', many times you'll have to WAIT outside or reduce/increase your boat speed to these smaller inlets so that your 'timing' is correct to safely enter, ....... or simply travel on to the next (or turn back to 'the last') inlet so the 'timing' is more correct. Many of these minor inlets will NOT be suitable for 'sailboats' in any conditions --- without specific 'local knowledge'. When in doubt, contact the local USCG on VHF channel 22a
for specific inlet info.
You usually don't use such inlets when there is a large/high easterly (NE/E/SE) swell and an outflowing
/ebbing current. When 'shooting' such inlets, you want to preferentially do so on 'slack' current or a flooding ('in') current - for less 'standing
waves' height. What you don't want to do is to blindly enter (or cross the 'outer bar') and find the standing waves are much larger than what your boat can safely handle and then find you CANNOT do a 180° without broaching, etc. - trapped!!! Correct 'timing' will help you avoid this.
If in doubt and you do decide to enter in 'boisterous' inlet conditions, consider to have the boat totally
closed up, including the companionway, and with PFDs, etc. 'on'. Some of the east coast inlets are notoriously bad
during the wrong
conditions; and the prudent sailor will usually 'stay out' and not enter during the 'wrong' inlet conditions (and especially with a dirty, crudded-up fuel tank !!!!).
For the Southeast, mid-Atlantic and New England coasts, the best reference is "Eldridge" Tide and Current tables ..... Eldridge Tide and Pilot Book 2016
"Eldridge" is based on 'historical
' data, not 'just' computer generated data.
Do consider to have an accurate *tide and current
* program as a backup for your tablet, smartphone, etc.