dinonline answers your question here and writes Birkat ha-gomel should not be recited for a short fishing trip
Shut Kinyan Torah (Vol. 1, no. 16, sec. 3) writes that somebody who
sails across the Channel between England and France does not recite
the blessing because the journey is short: Just as those who cross the
desert only recite ha-gomel after a lengthy journey, so in sailing on
the sea ha-gomel is only recited after a trip of significant length.
The same principle applies to other short sailing trips, such as a
short cruise or a fishing trip, after which ha-gomel is not recited.
Rav Shlomo Zalman Auerbach (Halichos Shlomo Chap. 23, Devar Halachah
5) writes that somebody who sails on the Kinneret, or near the shore,
should not recite ha-gomel, because in case of trouble help can be
given from the shore.
This might be a machloket Ashkenazim-Sefaradim though as R Yirmiyohu Kaganoff notes here
The Biur Halacha discusses whether one travelling a short trip by
river on a raft should recite birchas hagomeil. He says that it
depends on the above-mentioned dispute between Ashkenazim and Sefardim
whether one recites birchas hagomeil for a short intercity land trip.
According to minhag Ashkenaz, that one does not recite birchas
hagomeil for a short trip, one should not recite birchas hagomeil for
a trip by raft; whereas, according to minhag Sefard, which recites
birchas hagomeil even for a short intercity trip, one should recite
birchas hagomeil for a short river trip.
(by minhag Sefard I believe he means Sefaradi/Edot HaMizrach)