You can visit Bursa on
a long day-trip from Istanbul.
There's a lot to see
and you'll see more if you
stay overnight, but
if you can't, it's still a worthwhile
İznik on the Way & Overnight
If you can stay at least one night
in Bursa, consider visiting İznik (Nicaea)
along the way to Bursa.
I suggest visiting İznik on the way
to Bursa rather than on the return
from Bursa because for the return you can choose any of three docks and ferry lines to use.
Going By Seaplane
Seaplane flights one or both ways between Istanbul's Golden Horn and Bursa's Gemlik port can substantially reduce your travel time, though at added expense. You may decide to fly from Istanbul to Bursa, then take a ferry back to Istanbul at the end of the day to maintain your budget.
1-Day Istanbul - Bursa Excursion
Here is an example of how you might make an excursion to Bursa in one long day. Note that transport schedules may change from season to season, and there can be traffic and weather-related delays. Check the ferry schedules in advance!) Choose a fair weather day to sail on the ferry—no high wind or bad weather—, and try to avoid morning and late afternoon rush road traffic.
I cannot guarantee that you will be able to achieve this schedule, but it gives you an idea of possibilities.
07:00 to 07:30 am — Hotel to Ferry Dock
Go from your hotel to the appropriate Istanbul ferry dock, Kabataş or Yenikapı, depending on the ferry departure you want. You must be present to board 15 to 30 minutes before departure, and you may need some time to buy or print your ticket before boarding. (Don't forget: to print your ticket you must have the same credit card with which you made your reservation!)
I'd suggest that you plan to get to the ferry dock a minimum 45 minutes before departure time.
am to 010:30 am — Ferry Voyage
If you plan to visit İznik (Nicaea) on your way to Bursa, and stay overnight in Bursa, you will take the Istanbul (Yenikapı) to Yalova ferry, which takes about 1.25 hours. More...
Otherwise, you'll take either the BUDO or İDO ferries to Mudanya or Güzelyalı, a voyage of 2 hours. More...
11:00 am to 12:00 pm— Bus & Bursaray Metro from
Ferry Dock to Bursa
After leaving the ferry, board one of the waiting yellow city
buses, or a more
expensive taxi, and ride along a four-lane
road for 20 to 30 minutes to the Emek İstasyonu terminus of the Bursaray (Metro)
Line M1. Then take the Bursaray Metro train to the Şehreküstü station for central Bursa. More...
12:00 to 16:30 (4:30 pm) — See the Sights in Bursa
It's not much time, but enough to see most of the major sights. Here they are.
17:00 to 19:00 (5 to 7 pm) — Bursa to Ferry Dock
Make the trip by Bursaray and bus back to your ferry dock, arriving a minimum 30 minutes before departure time. If you're pressed for time, you may decide to take a taxi instead of a bus from the Bursaray Emek station to the ferry dock, but I doubt there would be any advantage in taking a taxi all the way from the center of Bursa. Taxis get stuck in traffic. Bursaray Metro trains do not.
19:30 to 21:30 (7:30 to 9:30 pm) — Ferry to Istanbul
You can rest on the ferry and buy some snacks and soft drinks from the refreshments counter.
21:30 to 22:00 (9:30 to 10 pm) — Ferry Dock to Hotel
Istanbul traffic is not heavy at this time of day, so you should reach your hotel—and bed—in good time.
—by Tom Brosnahan