We present a multi-band, multi-constellation Global Navigation Satellite System (GNSS) dataset comprising 216 daily files (two partial) recorded between 26 September 2025 and 29 April 2026 aboard the Italian research icebreaker R/V <em>Laura Bassi</em> during a round-trip voyage from Trieste to the Ross Sea sector of Antarctica and back, transiting the Panama Canal westbound on the outbound leg and Cape Horn (Drake Passage region) eastbound on the return. The route spans approximately 120° of geographic latitude (from 45.6° N to 74.8° S), includes eight crossings of the Antarctic Circle and two dwells in the Ross Sea. The instrument is a u-blox ZED-F9P-15B receiver paired with an NGS-calibrated Tersus AX4E02 multi-band geodetic-grade antenna, tracking GPS, GLONASS, Galileo, BeiDou, SBAS, QZSS and (where visible) NavIC across the L1 and L5 RF blocks. The release contains 37 144 455 high-precision navigation epochs and approximately 2.48 billion raw signal measurements at 2 Hz, together with approximately 18.6 million on-board radio-frequency spectrum messages (UBX-MON-SPAN, 1 Hz, one spectrum per RF block). On the basis of a structured literature and repository survey, we are not aware of a prior multi-month shipborne Antarctic GNSS dataset that preserves multi-band carrier-phase observables alongside dual-RF-block on-board UBX-MON-SPAN spectrum across both the L1 and L5 receiver blocks. Quality assessment finds a 3-D fix on every epoch after cold-start, 31.2 mean tracked satellites, code multipath of 0.4–1.0 m above 30° elevation, and best within-berth horizontal repeatability of 0.115 m at the Trieste return pier (cross-cluster median 0.57 m, <em>n</em> = 10 berths). Lyttelton (New Zealand) and its approaches account for nine of ten cruise-wide strong L-band RFI days. The deposit ships the raw binary .ubx alongside Hatanaka-compressed RINEX 3.04 (OBS+NAV) and the NGS-calibrated AX4E02 ATX. The open-source Python pipeline that produces the derived analyses referenced in this paper is bundled in the same Zenodo deposit under the MIT licence, with the development repository mirrored on GitHub. Use cases include kinematic positioning, tropospheric and precipitable-water-vapour retrieval, relative total-electron-content and rate-of-TEC products with a 2 Hz phasescintillation proxy (with bandwidth caveats), and shipborne L-band radio-frequency interference surveillance. The complete dataset is openly available at <a href="https://doi.org/10.5281/zenodo.20344101" target="_blank" rel="noopener">https://doi.org/10.5281/zenodo.20344101</a> (Blatnik et al., 2026).