The fourth season is the second to last season of the series. It was airing between 1998 to 1999. It had 30 episodes, all narrated by Denny Doherty.
Episodes
- Foduck's Hurt Feelings - Foduck discovers that it's OK to be angry as long as you talk about it afterward.
- Theodore's Tough Tugging - Theodore and George are having trouble getting along, but sleepy Northumberland and ultra-loud Owan provide an example of working together by accepting each other's differences.
- Theodore's Ocean Adventure - When Rebecca becomes trapped by a giant iceberg, Theodore discovers that he knows more than he thought he did about what to do.
- Theodore's New Job - When he is promoted to bell buoys, Theodore has to learn how to be a good boss.
- Digby's Disaster - The other ships ignore disaster-prone Digby while working on a big project, but a slipped cable gives him the chance to show how useful he can be.
- Dartmouth Says Goodbye - When it's time for him to leave the Big Harbour and go home, Dartmouth the cable ship helps Theodore understand that he's not losing a companion—he's gaining a friend in a whole new place.
- George's Funny Noise- Theodore learns that a very sensitive engine beats beneath George's bluster.
- Rebecca's Treasure - Theodore thinks that a day with Rebecca the Research Vessel will be boring—but is pleasantly surprised when he finally gives it a chance.
- Guysborough's Garbage - A giant supertanker helps the tugs see that everyone has an important part to play in making the Big Harbour a special place.
- Theodore's Visit to Ceilidh's Cove - Emily returns from her latest ocean-going adventure, and an envious Theodore wonders whether he'll ever be big enough to leave the harbour himself.
- George's Turn - George is sure he already has enough friends, until he discovers that he and Sigrid the Supply Ship have something unusual in common.
- Theodore Lands On Earth - After being tossed around all night by a storm, Theodore wishes he could live on land. But a stretch in dry dock changes his mind.
- Hank Makes a Friend - Hank discovers that the best way to make a friend is just to be himself.
- Foduck Blows His Stack - Foduck learns a lesson in patience.
- Sigrid and the Bumpers - Sigrid the Supply Ship reveals her secret dream: to be a tugboat.
- Hank's Wheezy Whistle - Hank manages to fix his malfunctioning whistle just in time for Tugboat Race Day.
- Theodore and the Haunted Houseboat - Once Foduck realizes how real Theodore's fears of the Haliburton Houseboat are, he also learns how he can be a better friend.
- Northumberland is Missing - Northumberland Submarine wanders off by himself, without telling anyone where he's going, and gets trapped in an underwater cave.
- Emily Goes Overboard - Emily discovers her limits while making tricky turns at Pictou Peaks.
- Emily and the Splash - Emily, Sigrid, and Theodore can't agree on the best way to explore a sandy shore, so they decide to take turns.
- Rebecca and the Big Snore - When Benjamin Bridge's snoring tries their patience, Rebecca and Theodore both realize that no one is perfect.
- Theodore and the Lies - Theodore tells a lie to get out of dock duty so he can go racing with Hank, and a fire breaks out while he should have been standing watch.
- Theodore's Bright Idea - Theodore makes the best of a bad situation when Lillie the Lighthouse is unable to warn an approaching ship because of her sore throat.
- George and the Navy Ship - While trying to be just like his hero, Nautilus the Navy ship, George discovers that some things aren't as easy as they look.
- Theodore's Prize - Theodore loses a tugging contest but learns that the best prize is a job well done.
- The Dispatcher's Best Birthday - The tugs run out of time while getting ready for the Dispatcher's birthday party.
- Emily's Easy Job - Theodore learns that everyone is good at doing different things.
- Nautilus and the Sinking Ship - The tugs learn the importance of asking for help while conducting a daring rescue operation.
- Owan On the Loose - Owan has to calm his own panic before he can rescue his friend Sigrid.
- Emily's Bruised Bumper - When she bruises her bumper and can't do her usual work, Emily worries that she's no longer important. But she learns that other things make her special, too.
Characters
- Theodore
- Emily
- Foduck
- Hank
- George
- Digby
- The Dispatcher
- Fundy
- Phillip and Filmore
- Owan
- Guysborough
- Benjamin Bridge
- Constance
- Bedford
- Lilly
- Barrington
- Rebecca
- Guysborough
- Bobby
- Northumberland
- Bingham
- Pearl
- Petra
- Bluenose
- Blandford
- Bingham
- Barrington (cameo)
Characters Introduced
- Sigrid
- Annapolis
- Nautilus
- Dartmouth
- Clementine
- Caroquette
- Canso Colossus
- Haliburton
- Shediac
- Truro
- Dorothy
- Inverness