Comparative study of global pooling for pre-departure ship fuel consumption prediction: Advantages over per-ship and adaptation-based approaches
Authors: Heungjun Im, Bongmin Cha, Agung Nugraha, Donghyun Kim, Seongphil Kang, Minwook Choi, Jeongmin Park, Jihwan Lee
Organizations: Department of Industrial and Data Engineering, Major in Industrial Data Science and Engineering, Pukyong National University, Busan, 48513, Republic of Korea · DX-Solutions Co., Ltd., Busan, Republic of Korea · Division of Mechanical, Shipbuilding & Air Conditioning Engineering, Pukyong National University, Busan, 48513, Republic of Korea · LAB021 Co., Ltd., Busan, Republic of Korea
Most fuel oil consumption (FOC) models for voyage planning are per-ship models and thus generalize poorly beyond each vessel's records. Transfer and federated learning have been reported to perform better, but under different protocols that often use inputs unavailable before departure or random data splits. It therefore remains unclear which approach performs best. In this study, we compare 11 per-ship, adaptation-based, and global methods on 21 vessels. To prevent leakage, all methods receive identical inputs known or forecast before departure, excluding engine RPM and shaft power, and are tested on intact voyage legs after all training records of each vessel. Global pooling, in which one model describes each vessel by its ship identity and seven ship specifications, performs best overall in every setting examined. For in-fleet vessels, Global LightGBM reaches an overall MAPE of 8.92%, against 11.14% for Per-Ship LightGBM, and outperforms every per-ship and adaptation-based model. Global models of five architectures, including a Transformer, all outperform the per-ship and federated models. Fine-tuning a global model for each vessel, even by low-rank adaptation of the Transformer, adds no accuracy. Without any records of a vessel, the global model reaches a median MAPE of 11.20% and outperforms a per-ship model trained on that vessel's records for 14 of 21 vessels. Adding its first records to the pooled data is as accurate as vessel-specific adaptation. Ship identity and specifications are largely interchangeable for in-fleet vessels, but only the specifications support zero-shot prediction. Its error grows as a vessel's specifications differ from the fleet's. Per-ship models and vessel-specific adaptation are therefore unnecessary under fair comparison. One global model can serve a whole fleet, including newly delivered vessels with similar specifications.
Figures & tables
Study
Approach
Nv
Period
Interval (R/P)
Nraw
Nobs
Plan. †
Temp. ‡
Evaluation
Luo et al. (2024)
Per-ship
1
∼ 18 mo.
daily / daily
335
168
✓
–
8:2 hold-out
Zhang et al. (2024)
Per-ship
1
29 mo.
60 s / –
1.0M
–
×
✓
5-fold CV + temporal holdout
Wang et al. (2023b)
Per-ship
1
∼ 7.5 mo.
10 min / 1 h
–
3,361
✓
×
interleaved split
Chen et al. (2024)
Per-ship
1
14–17 mo.
30 s / 1 min
1,237,562
65,560
×
✓
70/30 voyage hold-out
Son and Kim (2026)
Per-ship
1
18 mo.
10 s / 10 s
–
2.4M
✓
×
5-fold voyage CV
Mohamed et al. (2026)
Per-ship
1
12 mo.
daily / daily
296
266
×
✓
80:20 random split + chronological split
Table 1: Methodological comparison of FOC prediction studies. ✓ / × : criterion met/not met; –: not reported or not applicable.
Class
Type
Nv
DWT
MCR
LBP
B
Age
( ∼ kDWT)
( ∼ kW)
( ∼ m)
( ∼ m)
(yr)
A
Bulk carrier
8
400
29,000
350
65
9–15
B
Bulk carrier
11
320
21,000
330
62
4–7
C
Bulk carrier
1
180
19,000
280
45
∼ 15
D
Oil tanker
1
110
13,000
240
44
∼ 8
Total
21
4–15
Table 2: Fleet composition by vessel class. Specifications are approximate values representative of each class. All values are rounded to preserve confidentiality.
Figure 1: Data preprocessing pipeline. The raw 10-minute sensor records (about 4.0 million) are cleaned in three stages, averaged over 3-hour windows within voyage legs, and extended with derived features, resulting in 130,369 observations with 47 features.
Vessel
Class
ntrain
ntest
Vessel
Class
ntrain
ntest
Ship 1
B
4,304
1,304
Ship 12
B
5,715
1,842
Ship 2
B
7,392
1,917
Ship 13
A
600
224
Ship 3
D
5,877
1,530
Ship 14
A
5,983
1,878
Ship 4
B
4,826
1,523
Ship 15
A
1,774
501
Ship 5
B
5,918
1,631
Ship 16
A
2,877
856
Ship 6
B
7,717
2,134
Ship 17
B
5,776
1,713
Table 3: Number of observations per vessel. ntrain : observations in the training and validation partitions; ntest : observations in the temporal test set (Section 4.1 ). Vessels are anonymized as Ship 1–21.
Group
n
Features
Source before departure / description
Ship descriptors (8)
Ship identity
1
Ship name
Vessel registry
Ship specifications
7
MCR, DWT, LBP, breadth, propeller diameter, propeller pitch, ship age
Vessel registry and design documents
Operating state & environment (21)
Operational
5
SOG, course (sin/cos), mean draft, cargo quantity
Voyage plan (speed, course); loading plan (draft, cargo)
Environmental
12
Wind speed & dir. (sin/cos), current speed & dir. (sin/cos), wave height, dir. (sin/cos) & period, water depth, SST
Weather and ocean forecasts along the planned route; charts (water depth)
Table 4: The 47 features by group. For raw inputs, the last column gives where the value comes from before departure; derived features are computed from the raw inputs. Main-engine RPM and shaft power are excluded. Ship age is computed at 1 March 2026. The groups are those analyzed in the ablation (Section 5.3 ).
Figure 2: Training procedures of the compared methods: global pooling (a), the adaptation-based approaches of transfer (b) and federated learning (c), and per-ship modeling (d). (a) Global: a single model is trained on pooled fleet data. (b) Transfer: centralized pretraining followed by per-ship fine-tuning. (c) Federated: local training with weight averaging across R communication rounds, optionally followed by per-ship fine-tuning. (d) Per-ship: independent models trained on each vessel’s records with no data sharing.
Figure 3: Architecture of the global model. Four data sources feed a feature design stage that produces the 47 features of Table 4 , namely 29 raw inputs (the ship descriptors and the operating and environmental variables) and 18 derived features (the within-observation physics features and the cross-ship ratios). One model, encoding each vessel by its ship identity and ship specifications, is trained on the pooled records of all 21 vessels and predicts FOC without a vessel-specific stage. For an unseen vessel, the identity is unknown and the prediction rests on its ship specifications and operating inputs (zero-shot prediction).
Figure 4: Data partition. (a) The records of each vessel are split by voyage leg. The latest legs of each vessel form the test set, and the earlier legs are assigned at random, by whole leg, to training or validation. (b) Training procedure of the main comparison.
Partition
Voyage legs
Observations
Use
Training
548
82,472
Fitting during model selection
Validation
137
18,753
Hyperparameter and duration selection
Training + validation
685
101,225
Final fit with the selected configuration
Test
176
29,144
Evaluation only, latest legs of each vessel
Table 5: Data partitions. Voyage legs are never split between partitions; the test legs are the latest legs of each vessel.
Method
Approach
Base model
Training data
Per-ship stage
Nmodel
Global LGBM (ours)
Global
LightGBM
All fleet (pooled)
None
1
Global CatBoost
Global
CatBoost
All fleet (pooled)
None
1
TabM-FiLM
Global
TabM
All fleet (pooled)
None
1
Global ANN
Global
ANN [256,128,64]
All fleet (pooled)
None
1
F2V-Former
Global
Transformer (F2V)
All fleet (pooled)
None
1
ANN Transfer
Transfer
ANN [256,128,64]
All fleet → per-ship FT
Fine-tuning
21
Table 6: The 11 evaluated methods. “Training data” is the data seen in the main training phase; “Per-ship stage” indicates whether a separate per-ship fine-tuning or training step follows. Nmodel : number of models used at prediction time.
Method
Approach
MAPE overall
MAPE mean
R2
RMSE
MAE
Global LGBM (ours)
Global
8.92%
7.97%
0.774
0.228
0.168
F2V-Former
Global
9.09%
8.01%
0.790
0.219
0.162
TabM-FiLM
Global
9.11%
7.94%
0.794
0.218
0.163
Global CatBoost
Global
9.12%
8.24%
0.790
0.220
0.165
Global ANN
Global
9.69%
8.71%
0.757
0.236
0.175
F2V-Former + LoRA
Transfer
9.42%
8.24%
0.760
0.235
0.169
Table 7: Method comparison on the temporal test set (29,144 observations across 21 vessels). Methods are grouped by approach: global models (no per-ship stage), the adaptation-based transfer and federated models (pretraining ± per-ship fine-tuning), and per-ship models. Best in bold.
Figure 5: Overall MAPE comparison across all 11 methods, sorted in ascending order. Global LightGBM outperforms all other methods, and every global model outperforms the per-ship and federated models.
Figure 6: Per-ship MAPE heatmap for four key methods across 21 vessels. Global LightGBM achieves lower MAPE than Per-Ship LightGBM on 17 of 21 vessels, with the largest gains among data-scarce vessels.
Record MAPE
Leg-total error
Perturbation
Global LGBM
Per-ship LGBM
Gap (pp)
Global LGBM
Per-ship LGBM
None (recorded inputs)
8.92
11.14
2.22
9.32
10.97
Environment, s=10% , d=10∘
9.01
11.18
2.17
9.33
10.98
Environment, s=20% , d=20∘
9.28
11.35
2.07
9.42
11.05
Environment, s=30% , d=30∘
9.64
11.58
1.94
9.55
11.17
Speed, σ=0.25 kn
9.10
11.25
2.15
9.17
10.98
Table 8: Robustness of the global advantage to input perturbations (MAPE, %, mean of five draws; standard deviation across draws ≤0.4 pp). Environment: wind speed, wave height, wave period, and current speed scaled by 1+ε , ε∼N(0,s2) , with N(0,d2) added to their directions. Speed: N(0,σ2) added to speed over ground. Draws are independent per record unless marked per leg. Leg total: mean absolute percentage error of each test leg’s total FOC (176 legs).
Figure 7: Pooling gain (per-ship MAPE − global MAPE) of each vessel against its training set size, colored by vessel class. Positive values favor the global model. The three smallest training sets receive the three largest gains, and the four labeled vessels below zero are served better by their per-ship models. The fleet-wide rank correlation is weak (Spearman ρ=−0.39 , p=0.08 ).
Ship
Class
dNN
ntest
LOSO MAPE
Per-Ship LGBM
Global LGBM
Ship 3
D
2.856
1,530
38.37%
9.39%
9.26%
Ship 15
A
0.767
501
30.74%
50.75%
4.88%
Ship 7
C
2.856
1,970
21.36%
9.40%
11.72%
Ship 1
B
0.074
1,304
15.48%
20.67%
16.06%
Ship 5
B
0.074
1,631
14.36%
15.04%
14.52%
Ship 14
A
0.189
1,878
14.30%
3.90%
4.81%
Table 9: Zero-shot prediction in leave-one-ship-out (LOSO) tests for all 21 vessels. dNN : specification distance, that is, the Euclidean distance to the nearest other vessel in standardized specification space (Section 4.5 ). LOSO MAPE: error of Global LightGBM fitted without any records of the vessel. Per-Ship LGBM and Global LGBM: in-fleet errors of Per-Ship LightGBM and Global LightGBM on the same test legs (Table 7 ). Vessels are sorted by LOSO MAPE. Summary rows give the median and mean per-ship MAPE and the overall MAPE.
Figure 8: Zero-shot (leave-one-ship-out) error and specification distance. (a) Zero-shot MAPE of each vessel against its specification distance dNN to the nearest other vessel (log scale); the four vessels with dNN≥0.5 are labeled. (b) Zero-shot MAPE of the 17 vessels with dNN<0.5 and of the four vessels with dNN≥0.5 ; bars mark group medians. The 0.5 boundary is descriptive, not an applicability threshold.
LightGBM
F2V-Former
n (records)
Pooled refit
Adaptation
Per-ship
Pooled refit
LoRA
0 (zero-shot)
11.20 (12.48)
12.19 (13.01)
100
12.88 (12.67)
11.48 (12.37)
17.46 (21.99)
10.65 (10.31)
12.45 (13.10)
200
11.59 (12.78)
11.14 (12.78)
15.47 (20.20)
10.33 (9.96)
10.64 (11.19)
400 †
10.42 (11.80)
11.31 (11.85)
16.70 (18.68)
10.92 (10.31)
10.28 (10.99)
800 †
11.02 (10.95)
11.22 (11.29)
17.05 (18.90)
9.59 (9.51)
10.67 (10.99)
Table 10: Few-shot prediction for unseen vessels with their first n records: median (mean) per-ship MAPE (%) over the 21 vessels, evaluated on the original test legs of each vessel. Pooled refit: the n records are added to the pooled data and the global model is refitted with the fixed configuration of the LOSO tests. Adaptation: the zero-shot model is boosted further on the n records. Per-ship: a model fitted on the n records alone. F2V-Former (seed 42): the n records are added to the pooled data before refitting, or used for low-rank adaptation (LoRA) of its zero-shot model. Single seed. † Ship 8 (247 records) and, for n=800 , Ship 13 (600 records) use all their records.
Configuration
nfeat
In-fleet MAPE (%)
Δ (pp)
Feature ladder (objective fixed: direct MAPE)
Base features
34
12.00 ± 0.12
—
+ ship identity (categorical)
35
9.75 ± 0.10
− 2.25 ± 0.10
+ ship specifications
42
9.16 ± 0.04
− 0.60 ± 0.13
+ cross-ship ratios
47
9.06 ± 0.04
− 0.10 ± 0.06
Objective ladder (features fixed: full 47)
Table 11: In-fleet ablation: overall MAPE, mean ± standard deviation over five seeds, fixed hyperparameters. Δ : seed-paired change from the preceding row. The 35-, 42-, and 47-feature rows equal F4, F2, and F1 of Table 12 . † MAE with sample weights 1/yi .
Figure 9: Ablation results. (a) In-fleet feature ladder: overall MAPE as each feature group is added, training objective fixed at direct MAPE; numbers inside bars give the step change. (b) Feature-group contribution to accuracy ( Δ MAPE, positive = the group helps), in-fleet versus zero-shot. Both identity bars compare the base features with and without identity; with specifications present (F2 versus F2 - ), identity contributes +0.19 pp in-fleet and −0.06 pp under LOSO. Five seeds; error bars ±1 standard deviation.
Configuration
nfeat
In-fleet MAPE (%)
LOSO median (%)
LOSO mean (%)
F5 †
Raw
22
10.48
15.13
18.19
F3
Raw + specs
29
9.97 ± 0.13
11.48 ± 0.56
13.15 ± 0.20
F4
Raw + within
35
9.75 ± 0.10
16.00 ± 0.91
17.45 ± 0.16
F4 -
Raw + within, no identity
34
12.00 ± 0.12
14.12 ± 0.14
15.39 ± 0.11
F2
Raw + within + specs
42
9.16 ± 0.04
10.78 ± 0.25
12.77 ± 0.42
F2 -
Raw + within + specs, no identity
41
9.34 ± 0.10
10.72 ± 0.23
12.44 ± 0.16
Table 12: Zero-shot ablation: feature-group configurations evaluated in-fleet and leave-one-ship-out (LOSO median and mean over the 21 vessels, each predicted as an unseen vessel). Mean ± standard deviation over five seeds, fixed hyperparameters; F5 † : single seed. F1–F5 include ship identity; F2 - and F4 - omit it. raw = operational + environmental + maintenance; within = within-observation physics (13); specs = ship specifications (7); ratios = cross-ship ratios (5).
Figure 10: Top 15 features by mean ∣SHAP∣ value. Colors indicate feature groups: blue = cross-ship ratios, green = ship specifications, orange = ship identity, gray = base features.
Table 13: Quarterly retraining results (overall MAPE, %) of Global LightGBM with the hyperparameters of the main experiment. Static: trained once on the data up to 2023 Q2. Cumulative: retrained every quarter on all past data. Sliding 4Q/2Q: retrained every quarter on the latest four or two quarters. 2025Q3 contains July 2025 only, the last month of the dataset. Best per quarter in bold.
Appendix figures & tables6 assets
Supplementary material from the paper’s appendix.
Appendix
Method
Architecture
Optimizer
LR
Loss
BS
Max iter.
ES
Global LGBM
GBDT
—
HPO
Custom MAPE
—
3,000
50
CatBoost
Ordered GBDT
—
HPO
Native MAPE
—
3,000
50
TabM-FiLM
TabM + FiLM
AdamW
HPO
L1
HPO
200 ep.
25
Global ANN
[256,128,64] + emb(16)
Adam
10−3
L1
512
200 ep.
25
ANN Transfer
Global ANN → FT
Adam
5×10−5
L1
256
30 ep.
10
F2V-Former
Transformer (4 blocks)
Adam
3×10−4
L1
128
200 ep.
25
Appendix
Table 14: Training configuration for all 11 methods. LR: learning rate; BS: batch size; ES: early stopping patience.
Parameter
Global LGBM (30 trials)
CatBoost (30 trials)
Per-Ship LGBM (10 trials)
num_leaves / depth
[31,255]
depth [4,10]
[15,127]
max_depth
[4,12]
—
[3,10]
Learning rate
[5×10−3,0.2]
[5×10−3,0.2]
[5×10−3,0.2]
Subsample
[0.6,1.0]
[0.6,1.0]
[0.5,1.0]
Colsample
[0.6,1.0]
[0.6,1.0]
[0.5,1.0]
min_child_samples
[10,100]
[10,100]
adaptive †
Appendix
Table 15: HPO search space for tree-based models. Learning-rate and regularization ranges are sampled on a log scale; the remaining parameters use their stated integer or fractional bounds. Global and Per-Ship LightGBM share the custom MAPE objective.
Parameter
Range
Ensemble size k
{32,64}
Block dimension
{192,256,384}
Number of blocks
[2,4]
Learning rate
[5×10−5,2×10−3] (log)
Dropout
[0.05,0.45]
Weight decay
[10−5,10−2] (log)
Appendix
Table 16: HPO search space for TabM-FiLM (30 Optuna trials).
#
Layer
Input dim
Output dim
Notes
0
Embedding(21, 16)
ship index
16
Learned ship embedding
1
Concatenate
nc+16
62
Continuous features + embedding
2
FC block
62
256
Linear + BN + ReLU + Drop(0.2)
3
FC block
256
128
Linear + BN + ReLU + Drop(0.2)
4
FC block
128
64
Linear + BN + ReLU + Drop(0.2)
5
Linear
64
1
Output (FOC, t/h)
Appendix
Table 17: Global ANN architecture (also used as pretrained base for ANN Transfer). nc=46 continuous features.
#
Layer
Input dim
Output dim
Notes
1
FC block
nc=46
256
Linear + BN + ReLU + Drop(0.2)
2
FC block
256
128
Linear + BN + ReLU + Drop(0.2)
3
FC block
128
64
Linear + BN + ReLU + Drop(0.2)
4
Linear
64
1
Output (FOC, t/h)
Total parameters
54,145
Appendix
Table 18: FedANN architecture (used by FedAvg and FedAvg+FT). No ship embedding is included in this implementation. nc=46 continuous features.
#
Layer
Input dim
Output dim
Notes
1
FC block
nc=46
128
Linear + BN + ReLU + Drop(0.2)
2
FC block
128
64
Linear + BN + ReLU + Drop(0.2)
3
FC block
64
32
Linear + BN + ReLU + Drop(0.2)
4
Linear
32
1
Output (FOC, t/h)
Total parameters
16,833
Appendix
Table 19: Per-Ship ANN architecture. One independent model per vessel; no ship embedding needed. nc=46 continuous features (no ship identity).
Ship fuel consumption (SFC) prediction supports vessel operation optimisation, emissions estimation, and decision support systems (DSS) for sustainable maritime transportation. Numerous data-driven fuel models have been developed over the past two decades, but a critical and often overlooked limitation lies in their validation practices: most studies evaluate performance using random train--test splits, which, applied to high-frequency records, admit temporal leakage and yield optimistic results that do not reflect deployment conditions. This paper examines that gap using time-aware evaluation, specifically Time Series Cross-Validation (TSCV) and Blocked TSCV (BTSCV). Using the Canadian Coast Guard Ship (CCGS) Sir Wilfrid Laurier as a case study, six regression models and a physics baseline are tuned under three time-aware schemes and three feature configurations, then evaluated on a common chronological hold-out set drawn from approximately 3.88 million steady-state 1,Hz records.
National Research Council Canada, Ocean, Coastal and River Engineering, P.O. Box 12093, St. John’s, A1B 3T5, NL, Canada · Department of Computer Science, Memorial University of Newfoundland, 40 Arctic Avenue, St. John’s, A1B 3X5, NL, Canada
To reduce carbon emissions and minimize shipping costs, improving the fuel efficiency of ships is crucial. Various measures are taken to reduce the total fuel consumption of ships, including optimizing vessel parameters and selecting routes with the lowest fuel consumption. Different estimation methods are proposed for predicting fuel consumption, while various optimization methods are proposed to minimize fuel oil consumption. This paper provides a comprehensive review of methods for estimating and optimizing fuel oil consumption in maritime transport. Our novel contributions include categorizing fuel oil consumption & estimation methods into physics-based, machine-learning, and hybrid models, exploring their strengths and limitations. Furthermore, we highlight the importance of data fusion techniques, which combine AIS, onboard sensors, and meteorological data to enhance accuracy. We make the first attempt to discuss the emerging role of Explainable AI in enhancing model transparency for decision-making. Uniquely, key challenges, including data quality, availability, and the need for real-time optimization, are identified, and future research directions are proposed to address these gaps, with a focus on hybrid models, real-time optimization, and the standardization of datasets.
Dusica Marijan, Hamza Haruna Mohammed, Bakht Zaman
Simula Research Laboratory, Kristian Augusts 23, Oslo, 0164, Norway
Accurate multi-step port-of-call sequence prediction is vital for tactical resource orchestration and logistical efficiency. However, existing methods struggle with unreliable voyage schedules and the inability of AIS data to provide visibility beyond the immediate next port. To address this, this study proposes a Connectivity-Constrained and Retrieval-Enhanced (CCRE) deep learning framework. Inspired by Retrieval-Augmented Generation, CCRE introduces a retrieval-enhanced historical encoder that queries a global maritime database for contextually similar navigational precedents. Transforming these scenarios into candidate-level semantic representations compensates for data sparsity in long-tail routes and resolves routing ambiguities. Integrating this with a Transformer-based trajectory encoder, the architecture executes adaptive "middle fusion" via cross-attention. This dynamically shifts predictive reliance from real-time kinematics for short-term accuracy to historical context for long-term strategic stability. To ensure sequence-level coherence, forecasting is formulated as a joint sequence generation problem using an autoregressive Transformer decoder enriched with Scheduled Sampling and Gumbel-Softmax relaxation. This mitigates error accumulation, while topology masks strictly enforce maritime network reachability to eliminate operationally infeasible routes. Evaluated on a global dataset, CCRE achieves a 72.3% first-destination accuracy and a 61.4% average three-step accuracy, outperforming baselines like CatBoost and LSTM by average margins of 12.6% and 11.3%, respectively. Case studies further corroborate the model's scalability and ability to capture complex routing patterns across diverse international trade lanes.
Yanzhao Su, Fang He, Yineng Wang
Department of Industrial Engineering, Tsinghua University, Beijing 100084, P.R. China · Department of Logistics and Maritime Studies, The Hong Kong Polytechnic University, Hong Kong